64880640 has 216 divisors, whose sum is σ = 245365848. Its totient is φ = 15728640.

The previous prime is 64880587. The next prime is 64880657. The reversal of 64880640 is 4608846.

64880640 = 1059² + 1060² + ... + 1113².

64880640 is a `hidden beast` number, since 6 + 4 + 8 + 8 + 0 + 640 = 666.

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 = 64880595 and 64880604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5898235 + ... + 5898245.

It is an arithmetic number, because the mean of its divisors is an integer number (1135953).

Almost surely, 2^64880640 is an apocalyptic number.

64880640 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 64880640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122682924).

64880640 is an abundant number, since it is smaller than the sum of its proper divisors (180485208).

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

64880640 is an equidigital number, since it uses as much as digits as its factorization.

64880640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 64880640 is about 8054.8519539468. The cubic root of 64880640 is about 401.8263154060.

It can be divided in two parts, 648806 and 40, that added together give a palindrome (648846).

The spelling of 64880640 in words is "sixty-four million, eight hundred eighty thousand, six hundred forty".