20870231 has 2 divisors, whose sum is σ = 20870232. Its totient is φ = 20870230.

The previous prime is 20870219. The next prime is 20870249. The reversal of 20870231 is 13207802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20870231 - 2²² = 16675927 is a prime.

It is a super-2 number, since 2×20870231² = 871133083986722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 20870197 and 20870206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20170231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435115 + 10435116.

It is an arithmetic number, because the mean of its divisors is an integer number (10435116).

Almost surely, 2^20870231 is an apocalyptic number.

20870231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870231 is an equidigital number, since it uses as much as digits as its factorization.

20870231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20870231 is about 4568.3947946735. The cubic root of 20870231 is about 275.3229528156.

The spelling of 20870231 in words is "twenty million, eight hundred seventy thousand, two hundred thirty-one".