6464240640 has 880 divisors, whose sum is σ = 27463534560. Its totient is φ = 1433272320.

The previous prime is 6464240639. The next prime is 6464240641. The reversal of 6464240640 is 460424646.

It is a happy number.

6464240640 is a `hidden beast` number, since 6 + 4 + 6 + 4 + 2 + 4 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (6464240639) and next prime (6464240641).

It is a tau number, because it is divible by the number of its divisors (880).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 6464240595 and 6464240604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6464240641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 59304906 + ... + 59305014.

It is an arithmetic number, because the mean of its divisors is an integer number (31208562).

Almost surely, 2^6464240640 is an apocalyptic number.

6464240640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6464240640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13731767280).

6464240640 is an abundant number, since it is smaller than the sum of its proper divisors (20999293920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6464240640 is a wasteful number, since it uses less digits than its factorization.

6464240640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The square root of 6464240640 is about 80400.5014909733. The cubic root of 6464240640 is about 1862.8269188159.

The spelling of 6464240640 in words is "six billion, four hundred sixty-four million, two hundred forty thousand, six hundred forty".