20976905 has 12 divisors (see below), whose sum is σ = 25782660. Its totient is φ = 16384032.

The previous prime is 20976887. The next prime is 20976913. The reversal of 20976905 is 50967902.

It can be written as a sum of positive squares in 2 ways, for example, as 3579664 + 17397241 = 1892^2 + 4171^2 .

It is not a de Polignac number, because 20976905 - 2⁸ = 20976649 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8111 + ... + 10379.

It is an arithmetic number, because the mean of its divisors is an integer number (2148555).

Almost surely, 2^20976905 is an apocalyptic number.

It is an amenable number.

20976905 is a deficient number, since it is larger than the sum of its proper divisors (4805755).

20976905 is an equidigital number, since it uses as much as digits as its factorization.

20976905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2360 (or 2317 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 20976905 is about 4580.0551306726. The cubic root of 20976905 is about 275.7912418824.

The spelling of 20976905 in words is "twenty million, nine hundred seventy-six thousand, nine hundred five".