20936709 has 12 divisors (see below), whose sum is σ = 31059756. Its totient is φ = 13580352.

The previous prime is 20936683. The next prime is 20936711. The reversal of 20936709 is 90763902.

It can be written as a sum of positive squares in 2 ways, for example, as 18948609 + 1988100 = 4353^2 + 1410^2 .

It is not a de Polignac number, because 20936709 - 2⁵ = 20936677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20936719) by changing a digit.

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 in 11 ways as a sum of consecutive naturals, for example, 31104 + ... + 31769.

It is an arithmetic number, because the mean of its divisors is an integer number (2588313).

Almost surely, 2^20936709 is an apocalyptic number.

It is an amenable number.

20936709 is a deficient number, since it is larger than the sum of its proper divisors (10123047).

20936709 is a wasteful number, since it uses less digits than its factorization.

20936709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62916 (or 62913 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 20936709 is about 4575.6648697211. The cubic root of 20936709 is about 275.6149719461.

The spelling of 20936709 in words is "twenty million, nine hundred thirty-six thousand, seven hundred nine".