20874557 has 6 divisors (see below), whose sum is σ = 22944894. Its totient is φ = 18976760.

The previous prime is 20874509. The next prime is 20874571. The reversal of 20874557 is 75547802.

It can be written as a sum of positive squares in only one way, i.e., 12313081 + 8561476 = 3509^2 + 2926^2 .

It is not a de Polignac number, because 20874557 - 2⁶ = 20874493 is a prime.

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 20874557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20874257) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86138 + ... + 86379.

It is an arithmetic number, because the mean of its divisors is an integer number (3824149).

Almost surely, 2^20874557 is an apocalyptic number.

It is an amenable number.

20874557 is a deficient number, since it is larger than the sum of its proper divisors (2070337).

20874557 is a wasteful number, since it uses less digits than its factorization.

20874557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172539 (or 172528 counting only the distinct ones).

The product of its (nonzero) digits is 78400, while the sum is 38.

The square root of 20874557 is about 4568.8682406040. The cubic root of 20874557 is about 275.3419745634.

It can be divided in two parts, 208745 and 57, that added together give a palindrome (208802).

The spelling of 20874557 in words is "twenty million, eight hundred seventy-four thousand, five hundred fifty-seven".