31689031 has 8 divisors (see below), whose sum is σ = 34835328. Its totient is φ = 28587000.

The previous prime is 31689019. The next prime is 31689041. The reversal of 31689031 is 13098613.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31689031 - 2⁵ = 31688999 is a prime.

It is a super-2 number, since 2×31689031² = 2008389371437922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31688984 and 31689002.

It is a congruent number.

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

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 7 ways as a sum of consecutive naturals, for example, 9555 + ... + 12436.

It is an arithmetic number, because the mean of its divisors is an integer number (4354416).

Almost surely, 2^31689031 is an apocalyptic number.

31689031 is the 2518-th centered decagonal number.

31689031 is a deficient number, since it is larger than the sum of its proper divisors (3146297).

31689031 is a wasteful number, since it uses less digits than its factorization.

31689031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22133.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 31689031 is about 5629.3011111505. The cubic root of 31689031 is about 316.4484599541.

The spelling of 31689031 in words is "thirty-one million, six hundred eighty-nine thousand, thirty-one".