31993361 has 4 divisors (see below), whose sum is σ = 32133300. Its totient is φ = 31853424.

The previous prime is 31993349. The next prime is 31993363. The reversal of 31993361 is 16339913.

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 29637136 + 2356225 = 5444^2 + 1535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31993361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31993363) 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, 69626 + ... + 70083.

It is an arithmetic number, because the mean of its divisors is an integer number (8033325).

Almost surely, 2^31993361 is an apocalyptic number.

It is an amenable number.

31993361 is a deficient number, since it is larger than the sum of its proper divisors (139939).

31993361 is a wasteful number, since it uses less digits than its factorization.

31993361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139938.

The product of its digits is 13122, while the sum is 35.

The square root of 31993361 is about 5656.2674088130. The cubic root of 31993361 is about 317.4582531343.

The spelling of 31993361 in words is "thirty-one million, nine hundred ninety-three thousand, three hundred sixty-one".