99720631 has 2 divisors, whose sum is σ = 99720632. Its totient is φ = 99720630.

The previous prime is 99720619. The next prime is 99720637. The reversal of 99720631 is 13602799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 99720631 - 2²³ = 91332023 is a prime.

It is a super-2 number, since 2×99720631² = 19888408494076322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99720637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49860315 + 49860316.

It is an arithmetic number, because the mean of its divisors is an integer number (49860316).

Almost surely, 2^99720631 is an apocalyptic number.

99720631 is a deficient number, since it is larger than the sum of its proper divisors (1).

99720631 is an equidigital number, since it uses as much as digits as its factorization.

99720631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 99720631 is about 9986.0217804689. The cubic root of 99720631 is about 463.7262415448.

The spelling of 99720631 in words is "ninety-nine million, seven hundred twenty thousand, six hundred thirty-one".