64439833920 has 896 divisors, whose sum is σ = 268206833664. Its totient is φ = 12718080000.

The previous prime is 64439833901. The next prime is 64439833937. The reversal of 64439833920 is 2933893446.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 139782490 + ... + 139782950.

It is an arithmetic number, because the mean of its divisors is an integer number (299337984).

Almost surely, 2^64439833920 is an apocalyptic number.

64439833920 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 64439833920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134103416832).

64439833920 is an abundant number, since it is smaller than the sum of its proper divisors (203766999744).

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

64439833920 is a wasteful number, since it uses less digits than its factorization.

64439833920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591 (or 581 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 51.

The spelling of 64439833920 in words is "sixty-four billion, four hundred thirty-nine million, eight hundred thirty-three thousand, nine hundred twenty".