20945231 has 2 divisors, whose sum is σ = 20945232. Its totient is φ = 20945230.

The previous prime is 20945227. The next prime is 20945261. The reversal of 20945231 is 13254902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20945231 - 2² = 20945227 is a prime.

It is a super-2 number, since 2×20945231² = 877405403286722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20945231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20945261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10472615 + 10472616.

It is an arithmetic number, because the mean of its divisors is an integer number (10472616).

Almost surely, 2^20945231 is an apocalyptic number.

20945231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20945231 is an equidigital number, since it uses as much as digits as its factorization.

20945231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 20945231 is about 4576.5960057667. The cubic root of 20945231 is about 275.6523619705.

The spelling of 20945231 in words is "twenty million, nine hundred forty-five thousand, two hundred thirty-one".