18059621 has 2 divisors, whose sum is σ = 18059622. Its totient is φ = 18059620.

The previous prime is 18059617. The next prime is 18059659. The reversal of 18059621 is 12695081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15132100 + 2927521 = 3890^2 + 1711^2 .

It is a cyclic number.

It is not a de Polignac number, because 18059621 - 2² = 18059617 is a prime.

It is a super-2 number, since 2×18059621² = 652299821327282, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18059021) 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, 9029810 + 9029811.

It is an arithmetic number, because the mean of its divisors is an integer number (9029811).

Almost surely, 2^18059621 is an apocalyptic number.

It is an amenable number.

18059621 is a deficient number, since it is larger than the sum of its proper divisors (1).

18059621 is an equidigital number, since it uses as much as digits as its factorization.

18059621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 18059621 is about 4249.6612806199. The cubic root of 18059621 is about 262.3631746498.

The spelling of 18059621 in words is "eighteen million, fifty-nine thousand, six hundred twenty-one".