137479721 has 4 divisors (see below), whose sum is σ = 140073732. Its totient is φ = 134885712.

The previous prime is 137479711. The next prime is 137479739. The reversal of 137479721 is 127974731.

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 99780121 + 37699600 = 9989^2 + 6140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137479721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137479711) 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 3 ways as a sum of consecutive naturals, for example, 1296926 + ... + 1297031.

It is an arithmetic number, because the mean of its divisors is an integer number (35018433).

Almost surely, 2^137479721 is an apocalyptic number.

It is an amenable number.

137479721 is a deficient number, since it is larger than the sum of its proper divisors (2594011).

137479721 is an equidigital number, since it uses as much as digits as its factorization.

137479721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2594010.

The product of its digits is 74088, while the sum is 41.

The square root of 137479721 is about 11725.1746682086. The cubic root of 137479721 is about 516.1146824098.

The spelling of 137479721 in words is "one hundred thirty-seven million, four hundred seventy-nine thousand, seven hundred twenty-one".