23891009 has 2 divisors, whose sum is σ = 23891010. Its totient is φ = 23891008.

The previous prime is 23890957. The next prime is 23891027. The reversal of 23891009 is 90019832.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23668225 + 222784 = 4865^2 + 472^2 .

It is a cyclic number.

It is not a de Polignac number, because 23891009 - 2⁸ = 23890753 is a prime.

It is a super-2 number, since 2×23891009² = 1141560622076162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (23891029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11945504 + 11945505.

It is an arithmetic number, because the mean of its divisors is an integer number (11945505).

Almost surely, 2^23891009 is an apocalyptic number.

It is an amenable number.

23891009 is a deficient number, since it is larger than the sum of its proper divisors (1).

23891009 is an equidigital number, since it uses as much as digits as its factorization.

23891009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 23891009 is about 4887.8429802930. The cubic root of 23891009 is about 288.0126063476.

The spelling of 23891009 in words is "twenty-three million, eight hundred ninety-one thousand, nine".