64400643264 has 224 divisors, whose sum is σ = 180901969920. Its totient is φ = 20178183168.

The previous prime is 64400643247. The next prime is 64400643271. The reversal of 64400643264 is 46234600446.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 128032837 + ... + 128033339.

It is an arithmetic number, because the mean of its divisors is an integer number (807598080).

Almost surely, 2^64400643264 is an apocalyptic number.

64400643264 is a gapful number since it is divisible by the number (64) 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 64400643264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90450984960).

64400643264 is an abundant number, since it is smaller than the sum of its proper divisors (116501326656).

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

64400643264 is a wasteful number, since it uses less digits than its factorization.

64400643264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987 (or 977 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 39.

The spelling of 64400643264 in words is "sixty-four billion, four hundred million, six hundred forty-three thousand, two hundred sixty-four".