31689142 has 4 divisors (see below), whose sum is σ = 47533716. Its totient is φ = 15844570.

The previous prime is 31689137. The next prime is 31689143. The reversal of 31689142 is 24198613.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24198613 = 349 ⋅69337.

It is a junction number, because it is equal to n+sod(n) for n = 31689098 and 31689107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31689143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7922284 + ... + 7922287.

It is an arithmetic number, because the mean of its divisors is an integer number (11883429).

Almost surely, 2^31689142 is an apocalyptic number.

31689142 is a deficient number, since it is larger than the sum of its proper divisors (15844574).

31689142 is a wasteful number, since it uses less digits than its factorization.

31689142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15844573.

The product of its digits is 10368, while the sum is 34.

The square root of 31689142 is about 5629.3109702698. The cubic root of 31689142 is about 316.4488294378.

The spelling of 31689142 in words is "thirty-one million, six hundred eighty-nine thousand, one hundred forty-two".