137872326521 has 4 divisors (see below), whose sum is σ = 137883547044. Its totient is φ = 137861106000.

The previous prime is 137872326509. The next prime is 137872326533. The reversal of 137872326521 is 125623278731.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (137872326509) and next prime (137872326533).

It can be written as a sum of positive squares in 2 ways, for example, as 92620400896 + 45251925625 = 304336^2 + 212725^2 .

It is a cyclic number.

It is not a de Polignac number, because 137872326521 - 2⁶ = 137872326457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137872326421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5591810 + ... + 5616411.

It is an arithmetic number, because the mean of its divisors is an integer number (34470886761).

Almost surely, 2^137872326521 is an apocalyptic number.

It is an amenable number.

137872326521 is a deficient number, since it is larger than the sum of its proper divisors (11220523).

137872326521 is a wasteful number, since it uses less digits than its factorization.

137872326521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11220522.

The product of its digits is 846720, while the sum is 47.

The spelling of 137872326521 in words is "one hundred thirty-seven billion, eight hundred seventy-two million, three hundred twenty-six thousand, five hundred twenty-one".