137561 has 4 divisors (see below), whose sum is σ = 138624. Its totient is φ = 136500.

The previous prime is 137537. The next prime is 137567. The reversal of 137561 is 165731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 137561 - 2¹⁰ = 136537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137567) by changing a digit.

It is a nontrivial repunit in base 19.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305 + ... + 606.

It is an arithmetic number, because the mean of its divisors is an integer number (34656).

2¹³⁷⁵⁶¹ is an apocalyptic number.

It is an amenable number.

137561 is a deficient number, since it is larger than the sum of its proper divisors (1063).

137561 is an equidigital number, since it uses as much as digits as its factorization.

137561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062.

The product of its digits is 630, while the sum is 23.

The square root of 137561 is about 370.8921676175. The cubic root of 137561 is about 51.6216372610.

The spelling of 137561 in words is "one hundred thirty-seven thousand, five hundred sixty-one".