31491189 has 24 divisors (see below), whose sum is σ = 48682400. Its totient is φ = 19556640.

The previous prime is 31491149. The next prime is 31491193. The reversal of 31491189 is 98119413.

It is not a de Polignac number, because 31491189 - 2⁹ = 31490677 is a prime.

It is a Smith number, since the sum of its digits (36) 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 (31491149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8922 + ... + 11940.

Almost surely, 2^31491189 is an apocalyptic number.

It is an amenable number.

31491189 is a deficient number, since it is larger than the sum of its proper divisors (17191211).

31491189 is a wasteful number, since it uses less digits than its factorization.

31491189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3105 (or 3102 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 31491189 is about 5611.7010789956. The cubic root of 31491189 is about 315.7885308700.

The spelling of 31491189 in words is "thirty-one million, four hundred ninety-one thousand, one hundred eighty-nine".