64400512 has 64 divisors (see below), whose sum is σ = 142767360. Its totient is φ = 28687360.

The previous prime is 64400477. The next prime is 64400533. The reversal of 64400512 is 21500446.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74193 + ... + 75055.

It is an arithmetic number, because the mean of its divisors is an integer number (2230740).

Almost surely, 2^64400512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64400512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71383680).

64400512 is an abundant number, since it is smaller than the sum of its proper divisors (78366848).

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

64400512 is a wasteful number, since it uses less digits than its factorization.

64400512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941 (or 929 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 64400512 is about 8024.9929594985. The cubic root of 64400512 is about 400.8326654678.

Adding to 64400512 its reverse (21500446), we get a palindrome (85900958).

The spelling of 64400512 in words is "sixty-four million, four hundred thousand, five hundred twelve".