23687221 has 2 divisors, whose sum is σ = 23687222. Its totient is φ = 23687220.

The previous prime is 23687207. The next prime is 23687231. The reversal of 23687221 is 12278632.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22667121 + 1020100 = 4761^2 + 1010^2 .

It is a cyclic number.

It is not a de Polignac number, because 23687221 - 2⁵ = 23687189 is a prime.

It is a super-2 number, since 2×23687221² = 1122168877405682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23687231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11843610 + 11843611.

It is an arithmetic number, because the mean of its divisors is an integer number (11843611).

Almost surely, 2^23687221 is an apocalyptic number.

It is an amenable number.

23687221 is a deficient number, since it is larger than the sum of its proper divisors (1).

23687221 is an equidigital number, since it uses as much as digits as its factorization.

23687221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 31.

The square root of 23687221 is about 4866.9519208638. The cubic root of 23687221 is about 287.1913602781.

The spelling of 23687221 in words is "twenty-three million, six hundred eighty-seven thousand, two hundred twenty-one".