18648521 has 2 divisors, whose sum is σ = 18648522. Its totient is φ = 18648520.

The previous prime is 18648499. The next prime is 18648529. The reversal of 18648521 is 12584681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18361225 + 287296 = 4285^2 + 536^2 .

It is a cyclic number.

It is not a de Polignac number, because 18648521 - 2⁶ = 18648457 is a prime.

It is not a weakly prime, because it can be changed into another prime (18648529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9324260 + 9324261.

It is an arithmetic number, because the mean of its divisors is an integer number (9324261).

Almost surely, 2^18648521 is an apocalyptic number.

It is an amenable number.

18648521 is a deficient number, since it is larger than the sum of its proper divisors (1).

18648521 is an equidigital number, since it uses as much as digits as its factorization.

18648521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15360, while the sum is 35.

The square root of 18648521 is about 4318.3933354895. The cubic root of 18648521 is about 265.1844971286.

The spelling of 18648521 in words is "eighteen million, six hundred forty-eight thousand, five hundred twenty-one".