23985781 has 2 divisors, whose sum is σ = 23985782. Its totient is φ = 23985780.

The previous prime is 23985769. The next prime is 23985791. The reversal of 23985781 is 18758932.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22410756 + 1575025 = 4734^2 + 1255^2 .

It is a cyclic number.

It is not a de Polignac number, because 23985781 - 2⁷ = 23985653 is a prime.

It is a super-2 number, since 2×23985781² = 1150635380359922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23985721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11992890 + 11992891.

It is an arithmetic number, because the mean of its divisors is an integer number (11992891).

Almost surely, 2^23985781 is an apocalyptic number.

It is an amenable number.

23985781 is a deficient number, since it is larger than the sum of its proper divisors (1).

23985781 is an equidigital number, since it uses as much as digits as its factorization.

23985781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 43.

The square root of 23985781 is about 4897.5280499452. The cubic root of 23985781 is about 288.3929379562.

The spelling of 23985781 in words is "twenty-three million, nine hundred eighty-five thousand, seven hundred eighty-one".