31689420 has 96 divisors (see below), whose sum is σ = 102187008. Its totient is φ = 7187712.

The previous prime is 31689407. The next prime is 31689443. The reversal of 31689420 is 2498613.

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 31 ways as a sum of consecutive naturals, for example, 82549 + ... + 82931.

It is an arithmetic number, because the mean of its divisors is an integer number (1064448).

Almost surely, 2^31689420 is an apocalyptic number.

31689420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31689420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51093504).

31689420 is an abundant number, since it is smaller than the sum of its proper divisors (70497588).

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

31689420 is a wasteful number, since it uses less digits than its factorization.

31689420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599 (or 597 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 31689420 is about 5629.3356624028. The cubic root of 31689420 is about 316.4497548075.

The spelling of 31689420 in words is "thirty-one million, six hundred eighty-nine thousand, four hundred twenty".