253231991 has 2 divisors, whose sum is σ = 253231992. Its totient is φ = 253231990.

The previous prime is 253231939. The next prime is 253232003. The reversal of 253231991 is 199132352.

253231991 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 is a cyclic number.

It is not a de Polignac number, because 253231991 - 2²² = 249037687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (253231291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126615995 + 126615996.

It is an arithmetic number, because the mean of its divisors is an integer number (126615996).

Almost surely, 2^253231991 is an apocalyptic number.

253231991 is a deficient number, since it is larger than the sum of its proper divisors (1).

253231991 is an equidigital number, since it uses as much as digits as its factorization.

253231991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14580, while the sum is 35.

The square root of 253231991 is about 15913.2646242058. The cubic root of 253231991 is about 632.6636120559.

The spelling of 253231991 in words is "two hundred fifty-three million, two hundred thirty-one thousand, nine hundred ninety-one".