31689042 has 64 divisors (see below), whose sum is σ = 79847424. Its totient is φ = 8144640.

The previous prime is 31689041. The next prime is 31689043. The reversal of 31689042 is 24098613.

It is an interprime number because it is at equal distance from previous prime (31689041) and next prime (31689043).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 31688994 and 31689012.

It is not an unprimeable number, because it can be changed into a prime (31689041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51903 + ... + 52509.

It is an arithmetic number, because the mean of its divisors is an integer number (1247616).

Almost surely, 2^31689042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31689042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39923712).

31689042 is an abundant number, since it is smaller than the sum of its proper divisors (48158382).

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

31689042 is a wasteful number, since it uses less digits than its factorization.

31689042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743.

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

The square root of 31689042 is about 5629.3020881811. The cubic root of 31689042 is about 316.4484965696.

The spelling of 31689042 in words is "thirty-one million, six hundred eighty-nine thousand, forty-two".