641896636 has 24 divisors (see below), whose sum is σ = 1144185840. Its totient is φ = 315004032.

The previous prime is 641896631. The next prime is 641896639. The reversal of 641896636 is 636698146.

It is a self number, because there is not a number n which added to its sum of digits gives 641896636.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641896631) 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, 176856 + ... + 180448.

It is an arithmetic number, because the mean of its divisors is an integer number (47674410).

Almost surely, 2^641896636 is an apocalyptic number.

It is an amenable number.

641896636 is a deficient number, since it is larger than the sum of its proper divisors (502289204).

641896636 is a wasteful number, since it uses less digits than its factorization.

641896636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4413 (or 4411 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 49.

The square root of 641896636 is about 25335.6791106929. The cubic root of 641896636 is about 862.6243236316.

The spelling of 641896636 in words is "six hundred forty-one million, eight hundred ninety-six thousand, six hundred thirty-six".