231221933 has 2 divisors, whose sum is σ = 231221934. Its totient is φ = 231221932.

The previous prime is 231221929. The next prime is 231221941. The reversal of 231221933 is 339122132.

231221933 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 216766729 + 14455204 = 14723^2 + 3802^2 .

It is a cyclic number.

It is not a de Polignac number, because 231221933 - 2² = 231221929 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231221983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610966 + 115610967.

It is an arithmetic number, because the mean of its divisors is an integer number (115610967).

Almost surely, 2^231221933 is an apocalyptic number.

It is an amenable number.

231221933 is a deficient number, since it is larger than the sum of its proper divisors (1).

231221933 is an equidigital number, since it uses as much as digits as its factorization.

231221933 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 26.

The square root of 231221933 is about 15205.9834604671. The cubic root of 231221933 is about 613.7756796027.

The spelling of 231221933 in words is "two hundred thirty-one million, two hundred twenty-one thousand, nine hundred thirty-three".