64400918400 has 768 divisors, whose sum is σ = 290114764800. Its totient is φ = 13586227200.

The previous prime is 64400918381. The next prime is 64400918401. The reversal of 64400918400 is 481900446.

It is a happy number.

64400918400 is a `hidden beast` number, since 644 + 0 + 0 + 9 + 1 + 8 + 4 + 0 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64400918401) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 7858305 + ... + 7866495.

It is an arithmetic number, because the mean of its divisors is an integer number (377753600).

Almost surely, 2^64400918400 is an apocalyptic number.

64400918400 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 64400918400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145057382400).

64400918400 is an abundant number, since it is smaller than the sum of its proper divisors (225713846400).

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

64400918400 is a wasteful number, since it uses less digits than its factorization.

64400918400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8244 (or 8221 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 64400918400 in words is "sixty-four billion, four hundred million, nine hundred eighteen thousand, four hundred".