137998798849521 has 27 divisors (see below), whose sum is σ = 211747634476651. Its totient is φ = 86587105717824.

The previous prime is 137998798849519. The next prime is 137998798849559. The reversal of 137998798849521 is 125948897899731.

The square root of 137998798849521 is 11747289.

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

137998798849521 is a `hidden beast` number, since 1 + 3 + 7 + 9 + 9 + 8 + 7 + 98 + 8 + 495 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 107438511215025 + 30560287634496 = 10365255^2 + 5528136^2 .

It is not a de Polignac number, because 137998798849521 - 2¹ = 137998798849519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137998798849501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 598996570 + ... + 599226908.

Almost surely, 2^{137998798849521} is an apocalyptic number.

137998798849521 is the 11747289-th square number.

137998798849521 is the 5873645-th centered octagonal number.

It is an amenable number.

137998798849521 is a deficient number, since it is larger than the sum of its proper divisors (73748835627130).

137998798849521 is an frugal number, since it uses more digits than its factorization.

137998798849521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460718 (or 230359 counting only the distinct ones).

The product of its digits is 19752284160, while the sum is 90.

The spelling of 137998798849521 in words is "one hundred thirty-seven trillion, nine hundred ninety-eight billion, seven hundred ninety-eight million, eight hundred forty-nine thousand, five hundred twenty-one".