20661776 has 20 divisors (see below), whose sum is σ = 40447932. Its totient is φ = 10223616.

The previous prime is 20661763. The next prime is 20661803. The reversal of 20661776 is 67716602.

It can be written as a sum of positive squares in 2 ways, for example, as 8271376 + 12390400 = 2876^2 + 3520^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5105 + ... + 8208.

Almost surely, 2^20661776 is an apocalyptic number.

It is an amenable number.

20661776 is a deficient number, since it is larger than the sum of its proper divisors (19786156).

20661776 is a wasteful number, since it uses less digits than its factorization.

20661776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13418 (or 13412 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 20661776 is about 4545.5226322173. The cubic root of 20661776 is about 274.4032282088.

The spelling of 20661776 in words is "twenty million, six hundred sixty-one thousand, seven hundred seventy-six".