18335621 has 2 divisors, whose sum is σ = 18335622. Its totient is φ = 18335620.

The previous prime is 18335599. The next prime is 18335633. The reversal of 18335621 is 12653381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13322500 + 5013121 = 3650^2 + 2239^2 .

It is a cyclic number.

It is not a de Polignac number, because 18335621 - 2¹⁰ = 18334597 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 (18335671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9167810 + 9167811.

It is an arithmetic number, because the mean of its divisors is an integer number (9167811).

Almost surely, 2^18335621 is an apocalyptic number.

It is an amenable number.

18335621 is a deficient number, since it is larger than the sum of its proper divisors (1).

18335621 is an equidigital number, since it uses as much as digits as its factorization.

18335621 is an odious number, because the sum of its binary digits is odd.

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

The square root of 18335621 is about 4282.0113264680. The cubic root of 18335621 is about 263.6929635657.

The spelling of 18335621 in words is "eighteen million, three hundred thirty-five thousand, six hundred twenty-one".