20858157 has 12 divisors (see below), whose sum is σ = 30623164. Its totient is φ = 13677120.

The previous prime is 20858153. The next prime is 20858179. The reversal of 20858157 is 75185802.

20858157 is a `hidden beast` number, since 20 + 8 + 581 + 57 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 527076 + 20331081 = 726^2 + 4509^2 .

It is not a de Polignac number, because 20858157 - 2² = 20858153 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20858153) 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 11 ways as a sum of consecutive naturals, for example, 18448 + ... + 19545.

Almost surely, 2^20858157 is an apocalyptic number.

It is an amenable number.

20858157 is a deficient number, since it is larger than the sum of its proper divisors (9765007).

20858157 is a wasteful number, since it uses less digits than its factorization.

20858157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38060 (or 38057 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 20858157 is about 4567.0731327624. The cubic root of 20858157 is about 275.2698486183.

The spelling of 20858157 in words is "twenty million, eight hundred fifty-eight thousand, one hundred fifty-seven".