31523 has 4 divisors (see below), whose sum is σ = 32640. Its totient is φ = 30408.

The previous prime is 31517. The next prime is 31531. The reversal of 31523 is 32513.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31523 - 2⁸ = 31267 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a nialpdrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 31498 and 31507.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31523.

It is not an unprimeable number, because it can be changed into a prime (31513) 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, 515 + ... + 572.

It is an arithmetic number, because the mean of its divisors is an integer number (8160).

2³¹⁵²³ is an apocalyptic number.

31523 is a deficient number, since it is larger than the sum of its proper divisors (1117).

31523 is a wasteful number, since it uses less digits than its factorization.

31523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116.

The product of its digits is 90, while the sum is 14.

The square root of 31523 is about 177.5471768291. The cubic root of 31523 is about 31.5894826934.

Adding to 31523 its product of digits (90), we get a palindrome (31613).

Subtracting 31523 from its reverse (32513), we obtain a triangular number (990 = T₄₄).

The spelling of 31523 in words is "thirty-one thousand, five hundred twenty-three".