31893989 has 12 divisors (see below), whose sum is σ = 35647884. Its totient is φ = 28432512.

The previous prime is 31893977. The next prime is 31893991. The reversal of 31893989 is 98939813.

It can be written as a sum of positive squares in 2 ways, for example, as 19936225 + 11957764 = 4465^2 + 3458^2 .

It is a de Polignac number, because none of the positive numbers 2^k-31893989 is a prime.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31893089) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3539 + ... + 8735.

It is an arithmetic number, because the mean of its divisors is an integer number (2970657).

Almost surely, 2^31893989 is an apocalyptic number.

It is an amenable number.

31893989 is a deficient number, since it is larger than the sum of its proper divisors (3753895).

31893989 is a wasteful number, since it uses less digits than its factorization.

31893989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5252 (or 5233 counting only the distinct ones).

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

The square root of 31893989 is about 5647.4763390385. The cubic root of 31893989 is about 317.1292350888.

The spelling of 31893989 in words is "thirty-one million, eight hundred ninety-three thousand, nine hundred eighty-nine".