99640831 has 2 divisors, whose sum is σ = 99640832. Its totient is φ = 99640830.

The previous prime is 99640817. The next prime is 99640873. The reversal of 99640831 is 13804699.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99640831 - 2¹³ = 99632639 is a prime.

It is a super-2 number, since 2×99640831² = 19856590404741122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99640811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49820415 + 49820416.

It is an arithmetic number, because the mean of its divisors is an integer number (49820416).

Almost surely, 2^99640831 is an apocalyptic number.

99640831 is a deficient number, since it is larger than the sum of its proper divisors (1).

99640831 is an equidigital number, since it uses as much as digits as its factorization.

99640831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 99640831 is about 9982.0253956800. The cubic root of 99640831 is about 463.6025117840.

The spelling of 99640831 in words is "ninety-nine million, six hundred forty thousand, eight hundred thirty-one".