31981684 has 48 divisors (see below), whose sum is σ = 68076288. Its totient is φ = 12849408.

The previous prime is 31981639. The next prime is 31981711. The reversal of 31981684 is 48618913.

It is a super-2 number, since 2×31981684² = 2045656222951712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33664 + ... + 34600.

It is an arithmetic number, because the mean of its divisors is an integer number (1418256).

Almost surely, 2^31981684 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 31981684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34038144).

31981684 is an abundant number, since it is smaller than the sum of its proper divisors (36094604).

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

31981684 is a wasteful number, since it uses less digits than its factorization.

31981684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1024 (or 1022 counting only the distinct ones).

The product of its digits is 41472, while the sum is 40.

The square root of 31981684 is about 5655.2350967931. The cubic root of 31981684 is about 317.4196262547.

The spelling of 31981684 in words is "thirty-one million, nine hundred eighty-one thousand, six hundred eighty-four".