31769981 has 2 divisors, whose sum is σ = 31769982. Its totient is φ = 31769980.

The previous prime is 31769977. The next prime is 31770007. The reversal of 31769981 is 18996713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24344356 + 7425625 = 4934^2 + 2725^2 .

It is a cyclic number.

It is not a de Polignac number, because 31769981 - 2² = 31769977 is a prime.

It is a super-2 number, since 2×31769981² = 2018663385480722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31769911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15884990 + 15884991.

It is an arithmetic number, because the mean of its divisors is an integer number (15884991).

Almost surely, 2^31769981 is an apocalyptic number.

It is an amenable number.

31769981 is a deficient number, since it is larger than the sum of its proper divisors (1).

31769981 is an equidigital number, since it uses as much as digits as its factorization.

31769981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 44.

The square root of 31769981 is about 5636.4865829699. The cubic root of 31769981 is about 316.7176879317.

The spelling of 31769981 in words is "thirty-one million, seven hundred sixty-nine thousand, nine hundred eighty-one".