20831807 has 2 divisors, whose sum is σ = 20831808. Its totient is φ = 20831806.

The previous prime is 20831803. The next prime is 20831821. The reversal of 20831807 is 70813802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20831807 - 2² = 20831803 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20831807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20831803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10415903 + 10415904.

It is an arithmetic number, because the mean of its divisors is an integer number (10415904).

Almost surely, 2^20831807 is an apocalyptic number.

20831807 is a deficient number, since it is larger than the sum of its proper divisors (1).

20831807 is an equidigital number, since it uses as much as digits as its factorization.

20831807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 20831807 is about 4564.1874413744. The cubic root of 20831807 is about 275.1538841216.

The spelling of 20831807 in words is "twenty million, eight hundred thirty-one thousand, eight hundred seven".