13623581 has 2 divisors, whose sum is σ = 13623582. Its totient is φ = 13623580.

The previous prime is 13623563. The next prime is 13623593. The reversal of 13623581 is 18532631.

13623581 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13623481 + 100 = 3691^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 13623581 - 2¹⁸ = 13361437 is a prime.

It is a super-2 number, since 2×13623581² = 371203918527122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13623541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6811790 + 6811791.

It is an arithmetic number, because the mean of its divisors is an integer number (6811791).

Almost surely, 2^13623581 is an apocalyptic number.

It is an amenable number.

13623581 is a deficient number, since it is larger than the sum of its proper divisors (1).

13623581 is an equidigital number, since it uses as much as digits as its factorization.

13623581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 13623581 is about 3691.0135464395. The cubic root of 13623581 is about 238.8345171933.

The spelling of 13623581 in words is "thirteen million, six hundred twenty-three thousand, five hundred eighty-one".