20957805 has 48 divisors (see below), whose sum is σ = 40985280. Its totient is φ = 10153440.

The previous prime is 20957777. The next prime is 20957819. The reversal of 20957805 is 50875902.

It is not a de Polignac number, because 20957805 - 2²⁰ = 19909229 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20957805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15694 + ... + 16976.

It is an arithmetic number, because the mean of its divisors is an integer number (853860).

Almost surely, 2^20957805 is an apocalyptic number.

It is an amenable number.

20957805 is a deficient number, since it is larger than the sum of its proper divisors (20027475).

20957805 is a wasteful number, since it uses less digits than its factorization.

20957805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1319 (or 1302 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The square root of 20957805 is about 4577.9695280768. The cubic root of 20957805 is about 275.7075115085.

The spelling of 20957805 in words is "twenty million, nine hundred fifty-seven thousand, eight hundred five".