31722912 has 144 divisors (see below), whose sum is σ = 100212840. Its totient is φ = 9455616.

The previous prime is 31722907. The next prime is 31722919. The reversal of 31722912 is 21922713.

It can be written as a sum of positive squares in 4 ways, for example, as 31404816 + 318096 = 5604^2 + 564^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (31722919) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138414 + ... + 138642.

Almost surely, 2^31722912 is an apocalyptic number.

31722912 is a gapful number since it is divisible by the number (32) 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 31722912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50106420).

31722912 is an abundant number, since it is smaller than the sum of its proper divisors (68489928).

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

31722912 is a wasteful number, since it uses less digits than its factorization.

31722912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 284 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 31722912 is about 5632.3096505785. The cubic root of 31722912 is about 316.5611989801.

It can be divided in two parts, 3172 and 2912, that added together give a square (6084 = 78²).

The spelling of 31722912 in words is "thirty-one million, seven hundred twenty-two thousand, nine hundred twelve".