31289289 has 16 divisors (see below), whose sum is σ = 43417920. Its totient is φ = 20018880.

The previous prime is 31289281. The next prime is 31289303. The reversal of 31289289 is 98298213.

It is not a de Polignac number, because 31289289 - 2³ = 31289281 is a prime.

It is a super-2 number, since 2×31289289² = 1958039212251042, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31289289.

It is not an unprimeable number, because it can be changed into a prime (31289281) 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 15 ways as a sum of consecutive naturals, for example, 14754 + ... + 16740.

It is an arithmetic number, because the mean of its divisors is an integer number (2713620).

Almost surely, 2^31289289 is an apocalyptic number.

It is an amenable number.

31289289 is a deficient number, since it is larger than the sum of its proper divisors (12128631).

31289289 is a wasteful number, since it uses less digits than its factorization.

31289289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2200.

The product of its digits is 62208, while the sum is 42.

The square root of 31289289 is about 5593.6829549055. The cubic root of 31289289 is about 315.1122099606.

The spelling of 31289289 in words is "thirty-one million, two hundred eighty-nine thousand, two hundred eighty-nine".