664894440 has 256 divisors, whose sum is σ = 2602483200. Its totient is φ = 147806208.

The previous prime is 664894427. The next prime is 664894453. The reversal of 664894440 is 44498466.

It is an interprime number because it is at equal distance from previous prime (664894427) and next prime (664894453).

It is a super-4 number, since 4×664894440⁴ (a number of 36 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 278532 + ... + 280908.

It is an arithmetic number, because the mean of its divisors is an integer number (10165950).

Almost surely, 2^664894440 is an apocalyptic number.

664894440 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 664894440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1301241600).

664894440 is an abundant number, since it is smaller than the sum of its proper divisors (1937588760).

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

664894440 is a wasteful number, since it uses less digits than its factorization.

664894440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2441 (or 2431 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The square root of 664894440 is about 25785.5471146144. The cubic root of 664894440 is about 872.8056864913.

The spelling of 664894440 in words is "six hundred sixty-four million, eight hundred ninety-four thousand, four hundred forty".