20945885 has 32 divisors (see below), whose sum is σ = 27907200. Its totient is φ = 15033600.

The previous prime is 20945867. The next prime is 20945891. The reversal of 20945885 is 58854902.

It is not a de Polignac number, because 20945885 - 2¹⁴ = 20929501 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207335 + ... + 207435.

It is an arithmetic number, because the mean of its divisors is an integer number (872100).

Almost surely, 2^20945885 is an apocalyptic number.

20945885 is the 3737-th pentagonal number.

It is an amenable number.

20945885 is a deficient number, since it is larger than the sum of its proper divisors (6961315).

20945885 is a wasteful number, since it uses less digits than its factorization.

20945885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221.

The product of its (nonzero) digits is 115200, while the sum is 41.

The square root of 20945885 is about 4576.6674556931. The cubic root of 20945885 is about 275.6552309572.

The spelling of 20945885 in words is "twenty million, nine hundred forty-five thousand, eight hundred eighty-five".