31684993 has 8 divisors (see below), whose sum is σ = 32270216. Its totient is φ = 31104000.

The previous prime is 31684973. The next prime is 31684997. The reversal of 31684993 is 39948613.

It can be written as a sum of positive squares in 4 ways, for example, as 3732624 + 27952369 = 1932^2 + 5287^2 .

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 31684993 - 2²¹ = 29587841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31684997) 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, 16693 + ... + 18493.

It is an arithmetic number, because the mean of its divisors is an integer number (4033777).

Almost surely, 2^31684993 is an apocalyptic number.

It is an amenable number.

31684993 is a deficient number, since it is larger than the sum of its proper divisors (585223).

31684993 is a wasteful number, since it uses less digits than its factorization.

31684993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2115.

The product of its digits is 139968, while the sum is 43.

The square root of 31684993 is about 5628.9424406366. The cubic root of 31684993 is about 316.4350181508.

The spelling of 31684993 in words is "thirty-one million, six hundred eighty-four thousand, nine hundred ninety-three".