20877857 has 16 divisors (see below), whose sum is σ = 28033152. Its totient is φ = 15016320.

The previous prime is 20877851. The next prime is 20877869. The reversal of 20877857 is 75877802.

It is not a de Polignac number, because 20877857 - 2⁶ = 20877793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20877851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9428 + ... + 11429.

It is an arithmetic number, because the mean of its divisors is an integer number (1752072).

Almost surely, 2^20877857 is an apocalyptic number.

It is an amenable number.

20877857 is a deficient number, since it is larger than the sum of its proper divisors (7155295).

20877857 is a wasteful number, since it uses less digits than its factorization.

20877857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20888.

The product of its (nonzero) digits is 219520, while the sum is 44.

The square root of 20877857 is about 4569.2293660967. The cubic root of 20877857 is about 275.3564831449.

Subtracting 20877857 from its reverse (75877802), we obtain a palindrome (54999945).

The spelling of 20877857 in words is "twenty million, eight hundred seventy-seven thousand, eight hundred fifty-seven".