64644136 has 32 divisors (see below), whose sum is σ = 125199360. Its totient is φ = 31272192.

The previous prime is 64644133. The next prime is 64644187. The reversal of 64644136 is 63144646.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a pancake number, because a pancake can be divided into 64644136 parts by 11370 straight cuts.

It is not an unprimeable number, because it can be changed into a prime (64644131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38041 + ... + 39703.

It is an arithmetic number, because the mean of its divisors is an integer number (3912480).

Almost surely, 2^64644136 is an apocalyptic number.

It is an amenable number.

64644136 is a deficient number, since it is larger than the sum of its proper divisors (60555224).

64644136 is a wasteful number, since it uses less digits than its factorization.

64644136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1825 (or 1821 counting only the distinct ones).

The product of its digits is 41472, while the sum is 34.

The square root of 64644136 is about 8040.1577098960. The cubic root of 64644136 is about 401.3374729310.

The spelling of 64644136 in words is "sixty-four million, six hundred forty-four thousand, one hundred thirty-six".