20813907 has 4 divisors (see below), whose sum is σ = 27751880. Its totient is φ = 13875936.

The previous prime is 20813887. The next prime is 20813921. The reversal of 20813907 is 70931802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20813907 - 2²⁴ = 4036691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20813957) 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 3 ways as a sum of consecutive naturals, for example, 3468982 + ... + 3468987.

It is an arithmetic number, because the mean of its divisors is an integer number (6937970).

Almost surely, 2^20813907 is an apocalyptic number.

20813907 is a deficient number, since it is larger than the sum of its proper divisors (6937973).

20813907 is an equidigital number, since it uses as much as digits as its factorization.

20813907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6937972.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 20813907 is about 4562.2261013676. The cubic root of 20813907 is about 275.0750516917.

The spelling of 20813907 in words is "twenty million, eight hundred thirteen thousand, nine hundred seven".