20971885 has 16 divisors (see below), whose sum is σ = 27744192. Its totient is φ = 15091200.

The previous prime is 20971807. The next prime is 20971889. The reversal of 20971885 is 58817902.

It is not a de Polignac number, because 20971885 - 2⁷ = 20971757 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 (20971889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3370 + ... + 7300.

It is an arithmetic number, because the mean of its divisors is an integer number (1734012).

Almost surely, 2^20971885 is an apocalyptic number.

It is an amenable number.

20971885 is a deficient number, since it is larger than the sum of its proper divisors (6772307).

20971885 is a wasteful number, since it uses less digits than its factorization.

20971885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4044.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 20971885 is about 4579.5070695436. The cubic root of 20971885 is about 275.7692401859.

The spelling of 20971885 in words is "twenty million, nine hundred seventy-one thousand, eight hundred eighty-five".