137980921 has 4 divisors (see below), whose sum is σ = 148594852. Its totient is φ = 127366992.

The previous prime is 137980919. The next prime is 137980951. The reversal of 137980921 is 129089731.

It is the 4796-th star number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 27415696 + 110565225 = 5236^2 + 10515^2 .

It is a cyclic number.

It is not a de Polignac number, because 137980921 - 2¹ = 137980919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137980951) 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, 5306946 + ... + 5306971.

It is an arithmetic number, because the mean of its divisors is an integer number (37148713).

Almost surely, 2^137980921 is an apocalyptic number.

It is an amenable number.

137980921 is a deficient number, since it is larger than the sum of its proper divisors (10613931).

137980921 is a wasteful number, since it uses less digits than its factorization.

137980921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10613930.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 137980921 is about 11746.5280402338. The cubic root of 137980921 is about 516.7411092644.

The spelling of 137980921 in words is "one hundred thirty-seven million, nine hundred eighty thousand, nine hundred twenty-one".