23190991 has 2 divisors, whose sum is σ = 23190992. Its totient is φ = 23190990.

The previous prime is 23190989. The next prime is 23191019. The reversal of 23190991 is 19909132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 23190991 - 2¹ = 23190989 is a prime.

Together with 23190989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23190901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11595495 + 11595496.

It is an arithmetic number, because the mean of its divisors is an integer number (11595496).

Almost surely, 2^23190991 is an apocalyptic number.

23190991 is a deficient number, since it is larger than the sum of its proper divisors (1).

23190991 is an equidigital number, since it uses as much as digits as its factorization.

23190991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 23190991 is about 4815.7025448007. The cubic root of 23190991 is about 285.1717073422.

The spelling of 23190991 in words is "twenty-three million, one hundred ninety thousand, nine hundred ninety-one".