31994393 has 4 divisors (see below), whose sum is σ = 32066100. Its totient is φ = 31922688.

The previous prime is 31994377. The next prime is 31994399. The reversal of 31994393 is 39349913.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23309584 + 8684809 = 4828^2 + 2947^2 .

It is a cyclic number.

It is not a de Polignac number, because 31994393 - 2⁴ = 31994377 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31994393.

It is not an unprimeable number, because it can be changed into a prime (31994399) 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 3 ways as a sum of consecutive naturals, for example, 35180 + ... + 36077.

It is an arithmetic number, because the mean of its divisors is an integer number (8016525).

Almost surely, 2^31994393 is an apocalyptic number.

It is an amenable number.

31994393 is a deficient number, since it is larger than the sum of its proper divisors (71707).

31994393 is an equidigital number, since it uses as much as digits as its factorization.

31994393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71706.

The product of its digits is 78732, while the sum is 41.

The square root of 31994393 is about 5656.3586343159. The cubic root of 31994393 is about 317.4616664820.

The spelling of 31994393 in words is "thirty-one million, nine hundred ninety-four thousand, three hundred ninety-three".