31339728 has 60 divisors (see below), whose sum is σ = 100240608. Its totient is φ = 8953920.

The previous prime is 31339727. The next prime is 31339753. The reversal of 31339728 is 82793313.

It is a happy number.

It is a super-2 number, since 2×31339728² = 1964357102227968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 31339692 and 31339701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31339727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14538 + ... + 16553.

Almost surely, 2^31339728 is an apocalyptic number.

It is an amenable number.

31339728 is an abundant number, since it is smaller than the sum of its proper divisors (68900880).

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

31339728 is a wasteful number, since it uses less digits than its factorization.

31339728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31112 (or 31103 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 31339728 is about 5598.1897073965. The cubic root of 31339728 is about 315.2814415885.

The spelling of 31339728 in words is "thirty-one million, three hundred thirty-nine thousand, seven hundred twenty-eight".