18895621 has 2 divisors, whose sum is σ = 18895622. Its totient is φ = 18895620.

The previous prime is 18895609. The next prime is 18895631. The reversal of 18895621 is 12659881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13068225 + 5827396 = 3615^2 + 2414^2 .

It is a cyclic number.

It is not a de Polignac number, because 18895621 - 2⁵ = 18895589 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18895631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9447810 + 9447811.

It is an arithmetic number, because the mean of its divisors is an integer number (9447811).

Almost surely, 2^18895621 is an apocalyptic number.

It is an amenable number.

18895621 is a deficient number, since it is larger than the sum of its proper divisors (1).

18895621 is an equidigital number, since it uses as much as digits as its factorization.

18895621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 40.

The square root of 18895621 is about 4346.9093618340. The cubic root of 18895621 is about 266.3506268088.

The spelling of 18895621 in words is "eighteen million, eight hundred ninety-five thousand, six hundred twenty-one".