31725216 has 96 divisors (see below), whose sum is σ = 93985920. Its totient is φ = 10409472.

The previous prime is 31725209. The next prime is 31725241. The reversal of 31725216 is 61252713.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 31725216.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62821 + ... + 63323.

It is an arithmetic number, because the mean of its divisors is an integer number (979020).

Almost surely, 2^31725216 is an apocalyptic number.

31725216 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 31725216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46992960).

31725216 is an abundant number, since it is smaller than the sum of its proper divisors (62260704).

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

31725216 is a wasteful number, since it uses less digits than its factorization.

31725216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595 (or 581 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 31725216 is about 5632.5141810740. The cubic root of 31725216 is about 316.5688626244.

Adding to 31725216 its reverse (61252713), we get a palindrome (92977929).

The spelling of 31725216 in words is "thirty-one million, seven hundred twenty-five thousand, two hundred sixteen".