131621 has 4 divisors (see below), whose sum is σ = 150432. Its totient is φ = 112812.

The previous prime is 131617. The next prime is 131627. The reversal of 131621 is 126131.

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 not a de Polignac number, because 131621 - 2² = 131617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131596 and 131605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9395 + ... + 9408.

It is an arithmetic number, because the mean of its divisors is an integer number (37608).

2¹³¹⁶²¹ is an apocalyptic number.

It is an amenable number.

131621 is a deficient number, since it is larger than the sum of its proper divisors (18811).

131621 is an equidigital number, since it uses as much as digits as its factorization.

131621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18810.

The product of its digits is 36, while the sum is 14.

The square root of 131621 is about 362.7960859767. The cubic root of 131621 is about 50.8676563562.

Adding to 131621 its reverse (126131), we get a palindrome (257752).

The spelling of 131621 in words is "one hundred thirty-one thousand, six hundred twenty-one".