640156136 has 32 divisors (see below), whose sum is σ = 1249063200. Its totient is φ = 307325760.

The previous prime is 640156133. The next prime is 640156147. The reversal of 640156136 is 631651046.

It is not an unprimeable number, because it can be changed into a prime (640156133) 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, 4526 + ... + 36066.

It is an arithmetic number, because the mean of its divisors is an integer number (39033225).

Almost surely, 2^640156136 is an apocalyptic number.

It is an amenable number.

640156136 is a deficient number, since it is larger than the sum of its proper divisors (608907064).

640156136 is a wasteful number, since it uses less digits than its factorization.

640156136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31649 (or 31645 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 640156136 is about 25301.3070018132. The cubic root of 640156136 is about 861.8439504843.

The spelling of 640156136 in words is "six hundred forty million, one hundred fifty-six thousand, one hundred thirty-six".