31839989 has 2 divisors, whose sum is σ = 31839990. Its totient is φ = 31839988.

The previous prime is 31839979. The next prime is 31840001. The reversal of 31839989 is 98993813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27144100 + 4695889 = 5210^2 + 2167^2 .

It is an emirp because it is prime and its reverse (98993813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31839989 - 2⁸ = 31839733 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31839919) 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 as a sum of consecutive naturals, namely, 15919994 + 15919995.

It is an arithmetic number, because the mean of its divisors is an integer number (15919995).

Almost surely, 2^31839989 is an apocalyptic number.

It is an amenable number.

31839989 is a deficient number, since it is larger than the sum of its proper divisors (1).

31839989 is an equidigital number, since it uses as much as digits as its factorization.

31839989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 50.

The square root of 31839989 is about 5642.6934171546. The cubic root of 31839989 is about 316.9501558626.

The spelling of 31839989 in words is "thirty-one million, eight hundred thirty-nine thousand, nine hundred eighty-nine".