31489921 has 8 divisors (see below), whose sum is σ = 32961600. Its totient is φ = 30026832.

The previous prime is 31489919. The next prime is 31489943. The reversal of 31489921 is 12998413.

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

It is a cyclic number.

It is not a de Polignac number, because 31489921 - 2¹ = 31489919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31489901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6066 + ... + 9988.

It is an arithmetic number, because the mean of its divisors is an integer number (4120200).

Almost surely, 2^31489921 is an apocalyptic number.

It is an amenable number.

31489921 is a deficient number, since it is larger than the sum of its proper divisors (1471679).

31489921 is a wasteful number, since it uses less digits than its factorization.

31489921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4295.

The product of its digits is 15552, while the sum is 37.

The square root of 31489921 is about 5611.5880996381. The cubic root of 31489921 is about 315.7842923804.

The spelling of 31489921 in words is "thirty-one million, four hundred eighty-nine thousand, nine hundred twenty-one".