31978325 has 6 divisors (see below), whose sum is σ = 39653154. Its totient is φ = 25582640.

The previous prime is 31978321. The next prime is 31978333. The reversal of 31978325 is 52387913.

It can be written as a sum of positive squares in 3 ways, for example, as 10609 + 31967716 = 103^2 + 5654^2 .

It is not a de Polignac number, because 31978325 - 2² = 31978321 is a prime.

It is a super-2 number, since 2×31978325² = 2045226539611250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31978321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 639542 + ... + 639591.

It is an arithmetic number, because the mean of its divisors is an integer number (6608859).

Almost surely, 2^31978325 is an apocalyptic number.

It is an amenable number.

31978325 is a deficient number, since it is larger than the sum of its proper divisors (7674829).

31978325 is a wasteful number, since it uses less digits than its factorization.

31978325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1279143 (or 1279138 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 31978325 is about 5654.9381075304. The cubic root of 31978325 is about 317.4085131246.

The spelling of 31978325 in words is "thirty-one million, nine hundred seventy-eight thousand, three hundred twenty-five".