31989247 has 4 divisors (see below), whose sum is σ = 32000560. Its totient is φ = 31977936.

The previous prime is 31989229. The next prime is 31989259. The reversal of 31989247 is 74298913.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 31989247 - 2¹⁵ = 31956479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31989227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2779 + ... + 8467.

It is an arithmetic number, because the mean of its divisors is an integer number (8000140).

Almost surely, 2^31989247 is an apocalyptic number.

31989247 is a deficient number, since it is larger than the sum of its proper divisors (11313).

31989247 is an equidigital number, since it uses as much as digits as its factorization.

31989247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11312.

The product of its digits is 108864, while the sum is 43.

The square root of 31989247 is about 5655.9037297323. The cubic root of 31989247 is about 317.4446453190. Note that the first 3 decimals are identical.

The spelling of 31989247 in words is "thirty-one million, nine hundred eighty-nine thousand, two hundred forty-seven".