138980521 has 3 divisors (see below), whose sum is σ = 138992311. Its totient is φ = 138968732.

The previous prime is 138980507. The next prime is 138980549. The reversal of 138980521 is 125089831.

The square root of 138980521 is 11789.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 3956121 + 135024400 = 1989^2 + 11620^2 .

It is not a de Polignac number, because 138980521 - 2⁵ = 138980489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138980591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 5895 + ... + 17683.

Almost surely, 2^138980521 is an apocalyptic number.

138980521 is the 11789-th square number.

138980521 is the 5895-th centered octagonal number.

It is an amenable number.

138980521 is a deficient number, since it is larger than the sum of its proper divisors (11790).

138980521 is an frugal number, since it uses more digits than its factorization.

138980521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23578 (or 11789 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 37.

The cubic root of 138980521 is about 517.9859481984.

The spelling of 138980521 in words is "one hundred thirty-eight million, nine hundred eighty thousand, five hundred twenty-one".