137387692521 has 12 divisors (see below), whose sum is σ = 198453078772. Its totient is φ = 91589861376.

The previous prime is 137387692513. The next prime is 137387692529. The reversal of 137387692521 is 125296783731.

137387692521 is a `hidden beast` number, since 1 + 3 + 7 + 387 + 6 + 9 + 252 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (137387692513) and next prime (137387692529).

It can be written as a sum of positive squares in 2 ways, for example, as 59692262400 + 77695430121 = 244320^2 + 278739^2 .

It is not a de Polignac number, because 137387692521 - 2³ = 137387692513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137387692529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 386985 + ... + 651561.

Almost surely, 2^137387692521 is an apocalyptic number.

It is an amenable number.

137387692521 is a deficient number, since it is larger than the sum of its proper divisors (61065386251).

137387692521 is a wasteful number, since it uses less digits than its factorization.

137387692521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322280 (or 322277 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 54.

The spelling of 137387692521 in words is "one hundred thirty-seven billion, three hundred eighty-seven million, six hundred ninety-two thousand, five hundred twenty-one".