31381072 has 20 divisors (see below), whose sum is σ = 62285076. Its totient is φ = 15307520.

The previous prime is 31381061. The next prime is 31381073. The reversal of 31381072 is 27018313.

It can be written as a sum of positive squares in 2 ways, for example, as 5125696 + 26255376 = 2264^2 + 5124^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31381073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23263 + ... + 24574.

Almost surely, 2^31381072 is an apocalyptic number.

It is an amenable number.

31381072 is a deficient number, since it is larger than the sum of its proper divisors (30904004).

31381072 is a wasteful number, since it uses less digits than its factorization.

31381072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47886 (or 47880 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 31381072 is about 5601.8811126264. The cubic root of 31381072 is about 315.4200225414.

Adding to 31381072 its reverse (27018313), we get a palindrome (58399385).

The spelling of 31381072 in words is "thirty-one million, three hundred eighty-one thousand, seventy-two".