23555621 has 2 divisors, whose sum is σ = 23555622. Its totient is φ = 23555620.

The previous prime is 23555603. The next prime is 23555683. The reversal of 23555621 is 12655532.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16924996 + 6630625 = 4114^2 + 2575^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23555621 is a prime.

It is a Sophie Germain 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 (23555921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11777810 + 11777811.

It is an arithmetic number, because the mean of its divisors is an integer number (11777811).

Almost surely, 2^23555621 is an apocalyptic number.

It is an amenable number.

23555621 is a deficient number, since it is larger than the sum of its proper divisors (1).

23555621 is an equidigital number, since it uses as much as digits as its factorization.

23555621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9000, while the sum is 29.

The square root of 23555621 is about 4853.4133349633. The cubic root of 23555621 is about 286.6585189379.

The spelling of 23555621 in words is "twenty-three million, five hundred fifty-five thousand, six hundred twenty-one".