31736981 has 2 divisors, whose sum is σ = 31736982. Its totient is φ = 31736980.

The previous prime is 31736953. The next prime is 31736989. The reversal of 31736981 is 18963713.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27772900 + 3964081 = 5270^2 + 1991^2 .

It is a cyclic number.

It is not a de Polignac number, because 31736981 - 2¹⁴ = 31720597 is a prime.

It is a super-2 number, since 2×31736981² = 2014471925988722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31736989) 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 as a sum of consecutive naturals, namely, 15868490 + 15868491.

It is an arithmetic number, because the mean of its divisors is an integer number (15868491).

Almost surely, 2^31736981 is an apocalyptic number.

It is an amenable number.

31736981 is a deficient number, since it is larger than the sum of its proper divisors (1).

31736981 is an equidigital number, since it uses as much as digits as its factorization.

31736981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 38.

The square root of 31736981 is about 5633.5584669017. The cubic root of 31736981 is about 316.6079899900.

The spelling of 31736981 in words is "thirty-one million, seven hundred thirty-six thousand, nine hundred eighty-one".