230917991 has 2 divisors, whose sum is σ = 230917992. Its totient is φ = 230917990.

The previous prime is 230917969. The next prime is 230917993. The reversal of 230917991 is 199719032.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 230917991 - 2²² = 226723687 is a prime.

It is a super-4 number, since 4×230917991⁴ (a number of 35 digits) contains 4444 as substring.

Together with 230917993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (230917993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115458995 + 115458996.

It is an arithmetic number, because the mean of its divisors is an integer number (115458996).

Almost surely, 2^230917991 is an apocalyptic number.

230917991 is a deficient number, since it is larger than the sum of its proper divisors (1).

230917991 is an equidigital number, since it uses as much as digits as its factorization.

230917991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30618, while the sum is 41.

The square root of 230917991 is about 15195.9860160504. The cubic root of 230917991 is about 613.5066249531.

The spelling of 230917991 in words is "two hundred thirty million, nine hundred seventeen thousand, nine hundred ninety-one".