31989139 has 8 divisors (see below), whose sum is σ = 39371360. Its totient is φ = 25310016.

The previous prime is 31989137. The next prime is 31989161. The reversal of 31989139 is 93198913.

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 31989139 - 2¹ = 31989137 is a prime.

It is a super-2 number, since 2×31989139² = 2046610027922642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31989095 and 31989104.

It is not an unprimeable number, because it can be changed into a prime (31989137) 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, 175674 + ... + 175855.

It is an arithmetic number, because the mean of its divisors is an integer number (4921420).

Almost surely, 2^31989139 is an apocalyptic number.

31989139 is a deficient number, since it is larger than the sum of its proper divisors (7382221).

31989139 is a wasteful number, since it uses less digits than its factorization.

31989139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351549.

The product of its digits is 52488, while the sum is 43.

The square root of 31989139 is about 5655.8941821784. The cubic root of 31989139 is about 317.4442880734. Note that the first 3 decimals are identical.

The spelling of 31989139 in words is "thirty-one million, nine hundred eighty-nine thousand, one hundred thirty-nine".