20907811 has 16 divisors (see below), whose sum is σ = 22498560. Its totient is φ = 19393920.

The previous prime is 20907781. The next prime is 20907823. The reversal of 20907811 is 11870902.

20907811 is a nontrivial binomial coefficient, being equal to C(6467, 2).

It is a cyclic number.

It is not a de Polignac number, because 20907811 - 2¹⁷ = 20776739 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20907811.

It is not an unprimeable number, because it can be changed into a prime (20907311) 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 15 ways as a sum of consecutive naturals, for example, 93646 + ... + 93868.

It is an arithmetic number, because the mean of its divisors is an integer number (1406160).

Almost surely, 2^20907811 is an apocalyptic number.

20907811 is the 6466-th triangular number.

20907811 is the 2156-th centered nonagonal number.

20907811 is a deficient number, since it is larger than the sum of its proper divisors (1590749).

20907811 is a wasteful number, since it uses less digits than its factorization.

20907811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 20907811 is about 4572.5059868742. The cubic root of 20907811 is about 275.4881072333.

The spelling of 20907811 in words is "twenty million, nine hundred seven thousand, eight hundred eleven".