31853699981 has 2 divisors, whose sum is σ = 31853699982. Its totient is φ = 31853699980.

The previous prime is 31853699957. The next prime is 31853699993. The reversal of 31853699981 is 18999635813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23309655625 + 8544044356 = 152675^2 + 92434^2 .

It is a cyclic number.

It is not a de Polignac number, because 31853699981 - 2¹⁰ = 31853698957 is a prime.

It is a super-2 number, since 2×31853699981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31853695981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15926849990 + 15926849991.

It is an arithmetic number, because the mean of its divisors is an integer number (15926849991).

Almost surely, 2^31853699981 is an apocalyptic number.

It is an amenable number.

31853699981 is a deficient number, since it is larger than the sum of its proper divisors (1).

31853699981 is an equidigital number, since it uses as much as digits as its factorization.

31853699981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12597120, while the sum is 62.

The spelling of 31853699981 in words is "thirty-one billion, eight hundred fifty-three million, six hundred ninety-nine thousand, nine hundred eighty-one".