23191997 has 2 divisors, whose sum is σ = 23191998. Its totient is φ = 23191996.

The previous prime is 23191969. The next prime is 23192047. The reversal of 23191997 is 79919132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15413476 + 7778521 = 3926^2 + 2789^2 .

It is a cyclic number.

It is not a de Polignac number, because 23191997 - 2⁸ = 23191741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23191907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11595998 + 11595999.

It is an arithmetic number, because the mean of its divisors is an integer number (11595999).

Almost surely, 2^23191997 is an apocalyptic number.

It is an amenable number.

23191997 is a deficient number, since it is larger than the sum of its proper divisors (1).

23191997 is an equidigital number, since it uses as much as digits as its factorization.

23191997 is an evil number, because the sum of its binary digits is even.

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

The square root of 23191997 is about 4815.8069936408. The cubic root of 23191997 is about 285.1758307623.

The spelling of 23191997 in words is "twenty-three million, one hundred ninety-one thousand, nine hundred ninety-seven".