31689312 has 24 divisors (see below), whose sum is σ = 83184696. Its totient is φ = 10563072.

The previous prime is 31689277. The next prime is 31689337. The reversal of 31689312 is 21398613.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164953 + ... + 165144.

It is an arithmetic number, because the mean of its divisors is an integer number (3466029).

Almost surely, 2^31689312 is an apocalyptic number.

31689312 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

31689312 is an abundant number, since it is smaller than the sum of its proper divisors (51495384).

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

31689312 is a wasteful number, since it uses less digits than its factorization.

31689312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330110 (or 330102 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 31689312 is about 5629.3260697885. The cubic root of 31689312 is about 316.4493953120.

The spelling of 31689312 in words is "thirty-one million, six hundred eighty-nine thousand, three hundred twelve".