18937388627521 has 243 divisors, whose sum is σ = 26517096543249. Its totient is φ = 13475403841536.

The previous prime is 18937388627513. The next prime is 18937388627539. The reversal of 18937388627521 is 12572688373981.

The square root of 18937388627521 is 4351711.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 40 ways, for example, as 18657691497025 + 279697130496 = 4319455^2 + 528864^2 .

It is not a de Polignac number, because 18937388627521 - 2³ = 18937388627513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18937388627581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 195230810545 + ... + 195230810641.

Almost surely, 2^{18937388627521} is an apocalyptic number.

18937388627521 is the 4351711-st square number.

18937388627521 is the 2175856-th centered octagonal number.

It is an amenable number.

18937388627521 is a deficient number, since it is larger than the sum of its proper divisors (7579707915728).

18937388627521 is an equidigital number, since it uses as much as digits as its factorization.

18937388627521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326 (or 163 counting only the distinct ones).

The product of its digits is 243855360, while the sum is 70.

The spelling of 18937388627521 in words is "eighteen trillion, nine hundred thirty-seven billion, three hundred eighty-eight million, six hundred twenty-seven thousand, five hundred twenty-one".