99643931 has 2 divisors, whose sum is σ = 99643932. Its totient is φ = 99643930.

The previous prime is 99643883. The next prime is 99643933. The reversal of 99643931 is 13934699.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 99643931 - 2⁶ = 99643867 is a prime.

It is a super-2 number, since 2×99643931² = 19857825970265522, which contains 22 as substring.

Together with 99643933, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99643933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49821965 + 49821966.

It is an arithmetic number, because the mean of its divisors is an integer number (49821966).

Almost surely, 2^99643931 is an apocalyptic number.

99643931 is a deficient number, since it is larger than the sum of its proper divisors (1).

99643931 is an equidigital number, since it uses as much as digits as its factorization.

99643931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 44.

The square root of 99643931 is about 9982.1806735803. The cubic root of 99643931 is about 463.6073195617.

The spelling of 99643931 in words is "ninety-nine million, six hundred forty-three thousand, nine hundred thirty-one".