31310172 has 48 divisors (see below), whose sum is σ = 82405120. Its totient is φ = 10278576.

The previous prime is 31310171. The next prime is 31310189. The reversal of 31310172 is 27101313.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31310171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5073 + ... + 9399.

Almost surely, 2^31310172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31310172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41202560).

31310172 is an abundant number, since it is smaller than the sum of its proper divisors (51094948).

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

31310172 is a wasteful number, since it uses less digits than its factorization.

31310172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4407 (or 4399 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 31310172 is about 5595.5493027941. The cubic root of 31310172 is about 315.1822981074.

Adding to 31310172 its reverse (27101313), we get a palindrome (58411485).

The spelling of 31310172 in words is "thirty-one million, three hundred ten thousand, one hundred seventy-two".