31641 has 8 divisors (see below), whose sum is σ = 43200. Its totient is φ = 20592.

The previous prime is 31627. The next prime is 31643. The reversal of 31641 is 14613.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31641 - 2⁷ = 31513 is a prime.

It is an Ulam number.

31641 is a lucky number.

It is a nialpdrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 31641.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60 + ... + 258.

It is an arithmetic number, because the mean of its divisors is an integer number (5400).

2³¹⁶⁴¹ is an apocalyptic number.

31641 is the 113-rd centered pentagonal number.

It is an amenable number.

31641 is a deficient number, since it is larger than the sum of its proper divisors (11559).

31641 is a wasteful number, since it uses less digits than its factorization.

31641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255.

The product of its digits is 72, while the sum is 15.

The square root of 31641 is about 177.8791724739. The cubic root of 31641 is about 31.6288499013.

Subtracting from 31641 its sum of digits (15), we obtain a triangular number (31626 = T₂₅₁).

Adding to 31641 its product of digits (72), we get a palindrome (31713).

The spelling of 31641 in words is "thirty-one thousand, six hundred forty-one".