23405621 has 2 divisors, whose sum is σ = 23405622. Its totient is φ = 23405620.

The previous prime is 23405611. The next prime is 23405623. The reversal of 23405621 is 12650432.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13608721 + 9796900 = 3689^2 + 3130^2 .

It is a cyclic number.

It is not a de Polignac number, because 23405621 - 2²² = 19211317 is a prime.

Together with 23405623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23405623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11702810 + 11702811.

It is an arithmetic number, because the mean of its divisors is an integer number (11702811).

Almost surely, 2^23405621 is an apocalyptic number.

It is an amenable number.

23405621 is a deficient number, since it is larger than the sum of its proper divisors (1).

23405621 is an equidigital number, since it uses as much as digits as its factorization.

23405621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 23405621 is about 4837.9356134616. The cubic root of 23405621 is about 286.0487512050.

The spelling of 23405621 in words is "twenty-three million, four hundred five thousand, six hundred twenty-one".