641785136 has 40 divisors (see below), whose sum is σ = 1278657744. Its totient is φ = 311869440.

The previous prime is 641785127. The next prime is 641785153. The reversal of 641785136 is 631587146.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a junction number, because it is equal to n+sod(n) for n = 641785093 and 641785102.

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, 183920 + ... + 187376.

Almost surely, 2^641785136 is an apocalyptic number.

It is an amenable number.

641785136 is a deficient number, since it is larger than the sum of its proper divisors (636872608).

641785136 is a wasteful number, since it uses less digits than its factorization.

641785136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3789 (or 3783 counting only the distinct ones).

The product of its digits is 120960, while the sum is 41.

The square root of 641785136 is about 25333.4785609872. The cubic root of 641785136 is about 862.5743736468.

The spelling of 641785136 in words is "six hundred forty-one million, seven hundred eighty-five thousand, one hundred thirty-six".