137581 has 4 divisors (see below), whose sum is σ = 145692. Its totient is φ = 129472.

The previous prime is 137573. The next prime is 137587. The reversal of 137581 is 185731.

137581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 84681 + 52900 = 291^2 + 230^2 .

It is not a de Polignac number, because 137581 - 2³ = 137573 is a prime.

It is a super-2 number, since 2×137581² = 37857063122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137587) 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, 4030 + ... + 4063.

It is an arithmetic number, because the mean of its divisors is an integer number (36423).

2¹³⁷⁵⁸¹ is an apocalyptic number.

It is an amenable number.

137581 is a deficient number, since it is larger than the sum of its proper divisors (8111).

137581 is an equidigital number, since it uses as much as digits as its factorization.

137581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8110.

The product of its digits is 840, while the sum is 25.

The square root of 137581 is about 370.9191286521. The cubic root of 137581 is about 51.6241388972.

It can be divided in two parts, 137 and 581, that multiplied together give a palindrome (79597).

The spelling of 137581 in words is "one hundred thirty-seven thousand, five hundred eighty-one".