31239989 has 8 divisors (see below), whose sum is σ = 35255520. Its totient is φ = 27420400.

The previous prime is 31239977. The next prime is 31240019. The reversal of 31239989 is 98993213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31239989 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 (31239919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48647 + ... + 49284.

It is an arithmetic number, because the mean of its divisors is an integer number (4406940).

Almost surely, 2^31239989 is an apocalyptic number.

It is an amenable number.

31239989 is a deficient number, since it is larger than the sum of its proper divisors (4015531).

31239989 is a wasteful number, since it uses less digits than its factorization.

31239989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97971.

The product of its digits is 104976, while the sum is 44.

The square root of 31239989 is about 5589.2744609654. The cubic root of 31239989 is about 314.9466240291.

The spelling of 31239989 in words is "thirty-one million, two hundred thirty-nine thousand, nine hundred eighty-nine".