23649581 has 2 divisors, whose sum is σ = 23649582. Its totient is φ = 23649580.

The previous prime is 23649557. The next prime is 23649583. The reversal of 23649581 is 18594632.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21473956 + 2175625 = 4634^2 + 1475^2 .

It is a cyclic number.

It is not a de Polignac number, because 23649581 - 2¹⁸ = 23387437 is a prime.

It is a super-2 number, since 2×23649581² = 1118605362951122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 23649583, it forms a pair of twin primes.

It is a Chen 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 (23649583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11824790 + 11824791.

It is an arithmetic number, because the mean of its divisors is an integer number (11824791).

Almost surely, 2^23649581 is an apocalyptic number.

It is an amenable number.

23649581 is a deficient number, since it is larger than the sum of its proper divisors (1).

23649581 is an equidigital number, since it uses as much as digits as its factorization.

23649581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 38.

The square root of 23649581 is about 4863.0834868425. The cubic root of 23649581 is about 287.0391598765.

The spelling of 23649581 in words is "twenty-three million, six hundred forty-nine thousand, five hundred eighty-one".