31536 has 40 divisors (see below), whose sum is σ = 91760. Its totient is φ = 10368.

The previous prime is 31531. The next prime is 31541. The reversal of 31536 is 63513.

It is an interprime number because it is at equal distance from previous prime (31531) and next prime (31541).

It is a Harshad number since it is a multiple of its sum of digits (18).

Its product of digits (270) is a multiple of the sum of its prime factors (90).

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31531) by changing a digit.

31536 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 396 + ... + 468.

It is an arithmetic number, because the mean of its divisors is an integer number (2294).

2³¹⁵³⁶ is an apocalyptic number.

31536 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45880).

31536 is an abundant number, since it is smaller than the sum of its proper divisors (60224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31536 is a wasteful number, since it uses less digits than its factorization.

31536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 78 counting only the distinct ones).

The product of its digits is 270, while the sum is 18.

The square root of 31536 is about 177.5837830434. The cubic root of 31536 is about 31.5938245690.

It can be divided in two parts, 315 and 36, that added together give a triangular number (351 = T₂₆).

The spelling of 31536 in words is "thirty-one thousand, five hundred thirty-six".