31816481 has 2 divisors, whose sum is σ = 31816482. Its totient is φ = 31816480.

The previous prime is 31816471. The next prime is 31816487. The reversal of 31816481 is 18461813.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28718881 + 3097600 = 5359^2 + 1760^2 .

It is a cyclic number.

It is not a de Polignac number, because 31816481 - 2¹⁰ = 31815457 is a prime.

It is a super-2 number, since 2×31816481² = 2024576926446722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31816487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15908240 + 15908241.

It is an arithmetic number, because the mean of its divisors is an integer number (15908241).

Almost surely, 2^31816481 is an apocalyptic number.

It is an amenable number.

31816481 is a deficient number, since it is larger than the sum of its proper divisors (1).

31816481 is an equidigital number, since it uses as much as digits as its factorization.

31816481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 32.

The square root of 31816481 is about 5640.6099847446. The cubic root of 31816481 is about 316.8721334454.

The spelling of 31816481 in words is "thirty-one million, eight hundred sixteen thousand, four hundred eighty-one".