31636993 has 2 divisors, whose sum is σ = 31636994. Its totient is φ = 31636992.

The previous prime is 31636991. The next prime is 31637041. The reversal of 31636993 is 39963613.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29724304 + 1912689 = 5452^2 + 1383^2 .

It is a cyclic number.

It is not a de Polignac number, because 31636993 - 2¹ = 31636991 is a prime.

Together with 31636991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31636991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15818496 + 15818497.

It is an arithmetic number, because the mean of its divisors is an integer number (15818497).

Almost surely, 2^31636993 is an apocalyptic number.

It is an amenable number.

31636993 is a deficient number, since it is larger than the sum of its proper divisors (1).

31636993 is an equidigital number, since it uses as much as digits as its factorization.

31636993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78732, while the sum is 40.

The square root of 31636993 is about 5624.6771462903. The cubic root of 31636993 is about 316.2751469117.

The spelling of 31636993 in words is "thirty-one million, six hundred thirty-six thousand, nine hundred ninety-three".