135621 has 8 divisors (see below), whose sum is σ = 200960. Its totient is φ = 90396.

The previous prime is 135617. The next prime is 135623. The reversal of 135621 is 126531.

It is not a de Polignac number, because 135621 - 2² = 135617 is a prime.

It is a Duffinian number.

135621 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 135594 and 135603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2485 + ... + 2538.

It is an arithmetic number, because the mean of its divisors is an integer number (25120).

2¹³⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

135621 is a deficient number, since it is larger than the sum of its proper divisors (65339).

135621 is an equidigital number, since it uses as much as digits as its factorization.

135621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5032 (or 5026 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 135621 is about 368.2675657725. The cubic root of 135621 is about 51.3778169908.

The spelling of 135621 in words is "one hundred thirty-five thousand, six hundred twenty-one".