20876909 has 2 divisors, whose sum is σ = 20876910. Its totient is φ = 20876908.

The previous prime is 20876899. The next prime is 20876929. The reversal of 20876909 is 90967802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18088009 + 2788900 = 4253^2 + 1670^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20876909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20876929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10438454 + 10438455.

It is an arithmetic number, because the mean of its divisors is an integer number (10438455).

Almost surely, 2^20876909 is an apocalyptic number.

It is an amenable number.

20876909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20876909 is an equidigital number, since it uses as much as digits as its factorization.

20876909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 20876909 is about 4569.1256275134. The cubic root of 20876909 is about 275.3523153817.

The spelling of 20876909 in words is "twenty million, eight hundred seventy-six thousand, nine hundred nine".