137621 has 4 divisors (see below), whose sum is σ = 150144. Its totient is φ = 125100.

The previous prime is 137597. The next prime is 137623. The reversal of 137621 is 126731.

137621 = 9² + 10² + ... + 74².

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137621 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 137593 and 137602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137623) 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, 6245 + ... + 6266.

It is an arithmetic number, because the mean of its divisors is an integer number (37536).

2¹³⁷⁶²¹ is an apocalyptic number.

137621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

137621 is a deficient number, since it is larger than the sum of its proper divisors (12523).

137621 is a wasteful number, since it uses less digits than its factorization.

137621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12522.

The product of its digits is 252, while the sum is 20.

The square root of 137621 is about 370.9730448429. The cubic root of 137621 is about 51.6291414422.

Adding to 137621 its sum of digits (20), we get a square (137641 = 371²).

The spelling of 137621 in words is "one hundred thirty-seven thousand, six hundred twenty-one".