20775681 has 12 divisors (see below), whose sum is σ = 30051840. Its totient is φ = 13830840.

The previous prime is 20775661. The next prime is 20775697. The reversal of 20775681 is 18657702.

20775681 is a `hidden beast` number, since 20 + 77 + 568 + 1 = 666.

It is not a de Polignac number, because 20775681 - 2¹⁹ = 20251393 is a prime.

It is a super-2 number, since 2×20775681² = 863257842027522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20775631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8160 + ... + 10398.

It is an arithmetic number, because the mean of its divisors is an integer number (2504320).

Almost surely, 2^20775681 is an apocalyptic number.

It is an amenable number.

20775681 is a deficient number, since it is larger than the sum of its proper divisors (9276159).

20775681 is a wasteful number, since it uses less digits than its factorization.

20775681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3276 (or 3273 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The square root of 20775681 is about 4558.0347738910. The cubic root of 20775681 is about 274.9065511685.

The spelling of 20775681 in words is "twenty million, seven hundred seventy-five thousand, six hundred eighty-one".