20158631 has 4 divisors (see below), whose sum is σ = 20212200. Its totient is φ = 20105064.

The previous prime is 20158627. The next prime is 20158661. The reversal of 20158631 is 13685102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20158631 - 2² = 20158627 is a prime.

It is a super-2 number, since 2×20158631² = 812740807588322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20158631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20158661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26216 + ... + 26973.

It is an arithmetic number, because the mean of its divisors is an integer number (5053050).

Almost surely, 2^20158631 is an apocalyptic number.

20158631 is a deficient number, since it is larger than the sum of its proper divisors (53569).

20158631 is an equidigital number, since it uses as much as digits as its factorization.

20158631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53568.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 20158631 is about 4489.8364112738. The cubic root of 20158631 is about 272.1575239153.

The spelling of 20158631 in words is "twenty million, one hundred fifty-eight thousand, six hundred thirty-one".