137717521 has 2 divisors, whose sum is σ = 137717522. Its totient is φ = 137717520.

The previous prime is 137717497. The next prime is 137717533. The reversal of 137717521 is 125717731.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107412496 + 30305025 = 10364^2 + 5505^2 .

It is a cyclic number.

It is not a de Polignac number, because 137717521 - 2⁹ = 137717009 is a prime.

It is a super-2 number, since 2×137717521² = 37932231180770882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (137717551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68858760 + 68858761.

It is an arithmetic number, because the mean of its divisors is an integer number (68858761).

Almost surely, 2^137717521 is an apocalyptic number.

It is an amenable number.

137717521 is a deficient number, since it is larger than the sum of its proper divisors (1).

137717521 is an equidigital number, since it uses as much as digits as its factorization.

137717521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10290, while the sum is 34.

The square root of 137717521 is about 11735.3108608166. The cubic root of 137717521 is about 516.4120871831.

The spelling of 137717521 in words is "one hundred thirty-seven million, seven hundred seventeen thousand, five hundred twenty-one".