20890564 has 6 divisors (see below), whose sum is σ = 36558494. Its totient is φ = 10445280.

The previous prime is 20890511. The next prime is 20890579. The reversal of 20890564 is 46509802.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20520900 + 369664 = 4530^2 + 608^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2611317 + ... + 2611324.

Almost surely, 2^20890564 is an apocalyptic number.

It is an amenable number.

20890564 is a deficient number, since it is larger than the sum of its proper divisors (15667930).

20890564 is a wasteful number, since it uses less digits than its factorization.

20890564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5222645 (or 5222643 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 20890564 is about 4570.6196516446. The cubic root of 20890564 is about 275.4123357038.

The spelling of 20890564 in words is "twenty million, eight hundred ninety thousand, five hundred sixty-four".