20875831 has 2 divisors, whose sum is σ = 20875832. Its totient is φ = 20875830.

The previous prime is 20875823. The next prime is 20875843. The reversal of 20875831 is 13857802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20875831 - 2³ = 20875823 is a prime.

It is a super-2 number, since 2×20875831² = 871600639881122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20875861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10437915 + 10437916.

It is an arithmetic number, because the mean of its divisors is an integer number (10437916).

Almost surely, 2^20875831 is an apocalyptic number.

20875831 is a deficient number, since it is larger than the sum of its proper divisors (1).

20875831 is an equidigital number, since it uses as much as digits as its factorization.

20875831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 20875831 is about 4569.0076603131. The cubic root of 20875831 is about 275.3475759363.

The spelling of 20875831 in words is "twenty million, eight hundred seventy-five thousand, eight hundred thirty-one".