18598621 has 2 divisors, whose sum is σ = 18598622. Its totient is φ = 18598620.

The previous prime is 18598609. The next prime is 18598631. The reversal of 18598621 is 12689581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11655396 + 6943225 = 3414^2 + 2635^2 .

It is an emirp because it is prime and its reverse (12689581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18598621 - 2¹⁷ = 18467549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18598631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9299310 + 9299311.

It is an arithmetic number, because the mean of its divisors is an integer number (9299311).

Almost surely, 2^18598621 is an apocalyptic number.

It is an amenable number.

18598621 is a deficient number, since it is larger than the sum of its proper divisors (1).

18598621 is an equidigital number, since it uses as much as digits as its factorization.

18598621 is an odious number, because the sum of its binary digits is odd.

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

The square root of 18598621 is about 4312.6118536219. The cubic root of 18598621 is about 264.9477575905.

The spelling of 18598621 in words is "eighteen million, five hundred ninety-eight thousand, six hundred twenty-one".