23981813 has 2 divisors, whose sum is σ = 23981814. Its totient is φ = 23981812.

The previous prime is 23981773. The next prime is 23981821. The reversal of 23981813 is 31818932.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22819729 + 1162084 = 4777^2 + 1078^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23981813 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23981863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11990906 + 11990907.

It is an arithmetic number, because the mean of its divisors is an integer number (11990907).

Almost surely, 2^23981813 is an apocalyptic number.

It is an amenable number.

23981813 is a deficient number, since it is larger than the sum of its proper divisors (1).

23981813 is an equidigital number, since it uses as much as digits as its factorization.

23981813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The square root of 23981813 is about 4897.1229308646. The cubic root of 23981813 is about 288.3770340020.

The spelling of 23981813 in words is "twenty-three million, nine hundred eighty-one thousand, eight hundred thirteen".