99997631 has 4 divisors (see below), whose sum is σ = 100194600. Its totient is φ = 99800664.

The previous prime is 99997619. The next prime is 99997649. The reversal of 99997631 is 13679999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13679999 = 1229 ⋅11131.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99997631 is a prime.

It is a super-2 number, since 2×99997631² = 19999052411224322, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99997691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97721 + ... + 98738.

It is an arithmetic number, because the mean of its divisors is an integer number (25048650).

Almost surely, 2^99997631 is an apocalyptic number.

99997631 is a deficient number, since it is larger than the sum of its proper divisors (196969).

99997631 is a wasteful number, since it uses less digits than its factorization.

99997631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196968.

The product of its digits is 826686, while the sum is 53.

The square root of 99997631 is about 9999.8815492985. The cubic root of 99997631 is about 464.1552180244.

The spelling of 99997631 in words is "ninety-nine million, nine hundred ninety-seven thousand, six hundred thirty-one".