641991136 has 12 divisors (see below), whose sum is σ = 1263920112. Its totient is φ = 320995552.

The previous prime is 641991131. The next prime is 641991137. The reversal of 641991136 is 631199146.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641991131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10031080 + ... + 10031143.

It is an arithmetic number, because the mean of its divisors is an integer number (105326676).

Almost surely, 2^641991136 is an apocalyptic number.

It is an amenable number.

641991136 is a deficient number, since it is larger than the sum of its proper divisors (621928976).

641991136 is a wasteful number, since it uses less digits than its factorization.

641991136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20062233 (or 20062225 counting only the distinct ones).

The product of its digits is 34992, while the sum is 40.

The square root of 641991136 is about 25337.5440009485. The cubic root of 641991136 is about 862.6666533952. Note that the first 4 decimals are identical.

The spelling of 641991136 in words is "six hundred forty-one million, nine hundred ninety-one thousand, one hundred thirty-six".