31698881 has 2 divisors, whose sum is σ = 31698882. Its totient is φ = 31698880.

The previous prime is 31698847. The next prime is 31698889. The reversal of 31698881 is 18889613.

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., 26946481 + 4752400 = 5191^2 + 2180^2 .

It is a cyclic number.

It is not a de Polignac number, because 31698881 - 2¹⁸ = 31436737 is a prime.

It is a super-2 number, since 2×31698881² = 2009638113304322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31698889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15849440 + 15849441.

It is an arithmetic number, because the mean of its divisors is an integer number (15849441).

Almost surely, 2^31698881 is an apocalyptic number.

It is an amenable number.

31698881 is a deficient number, since it is larger than the sum of its proper divisors (1).

31698881 is an equidigital number, since it uses as much as digits as its factorization.

31698881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 44.

The square root of 31698881 is about 5630.1759297557. The cubic root of 31698881 is about 316.4812441103.

The spelling of 31698881 in words is "thirty-one million, six hundred ninety-eight thousand, eight hundred eighty-one".