31249989 has 16 divisors (see below), whose sum is σ = 46388800. Its totient is φ = 20791728.

The previous prime is 31249979. The next prime is 31249991. The reversal of 31249989 is 98994213.

It is not a de Polignac number, because 31249989 - 2⁵ = 31249957 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 (31249909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19002 + ... + 20580.

It is an arithmetic number, because the mean of its divisors is an integer number (2899300).

Almost surely, 2^31249989 is an apocalyptic number.

It is an amenable number.

31249989 is a deficient number, since it is larger than the sum of its proper divisors (15138811).

31249989 is a wasteful number, since it uses less digits than its factorization.

31249989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2321 (or 2315 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 31249989 is about 5590.1689598795. The cubic root of 31249989 is about 314.9802255160.

The spelling of 31249989 in words is "thirty-one million, two hundred forty-nine thousand, nine hundred eighty-nine".