231790921 has 2 divisors, whose sum is σ = 231790922. Its totient is φ = 231790920.

The previous prime is 231790901. The next prime is 231790927. The reversal of 231790921 is 129097132.

It is a happy number.

231790921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 173054025 + 58736896 = 13155^2 + 7664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231790921 is a prime.

It is not a weakly prime, because it can be changed into another prime (231790927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115895460 + 115895461.

It is an arithmetic number, because the mean of its divisors is an integer number (115895461).

Almost surely, 2^231790921 is an apocalyptic number.

It is an amenable number.

231790921 is a deficient number, since it is larger than the sum of its proper divisors (1).

231790921 is an equidigital number, since it uses as much as digits as its factorization.

231790921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 231790921 is about 15224.6813102935. The cubic root of 231790921 is about 614.2787243352.

The spelling of 231790921 in words is "two hundred thirty-one million, seven hundred ninety thousand, nine hundred twenty-one".