31994681 has 2 divisors, whose sum is σ = 31994682. Its totient is φ = 31994680.

The previous prime is 31994647. The next prime is 31994741. The reversal of 31994681 is 18649913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27994681 + 4000000 = 5291^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 31994681 - 2¹⁸ = 31732537 is a prime.

It is a super-2 number, since 2×31994681² = 2047319224583522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31993681) 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 as a sum of consecutive naturals, namely, 15997340 + 15997341.

It is an arithmetic number, because the mean of its divisors is an integer number (15997341).

Almost surely, 2^31994681 is an apocalyptic number.

It is an amenable number.

31994681 is a deficient number, since it is larger than the sum of its proper divisors (1).

31994681 is an equidigital number, since it uses as much as digits as its factorization.

31994681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 41.

The square root of 31994681 is about 5656.3840923332. The cubic root of 31994681 is about 317.4626190310.

The spelling of 31994681 in words is "thirty-one million, nine hundred ninety-four thousand, six hundred eighty-one".