31689432 has 24 divisors (see below), whose sum is σ = 85825740. Its totient is φ = 10563120.

The previous prime is 31689407. The next prime is 31689443. The reversal of 31689432 is 23498613.

It is a tau number, because it is divible by the number of its divisors (24).

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 congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 219994 + ... + 220137.

Almost surely, 2^31689432 is an apocalyptic number.

It is an amenable number.

31689432 is an abundant number, since it is smaller than the sum of its proper divisors (54136308).

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

31689432 is a wasteful number, since it uses less digits than its factorization.

31689432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440143 (or 440136 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 31689432 is about 5629.3367282478. The cubic root of 31689432 is about 316.4497947514.

The spelling of 31689432 in words is "thirty-one million, six hundred eighty-nine thousand, four hundred thirty-two".