31861970281 has 2 divisors, whose sum is σ = 31861970282. Its totient is φ = 31861970280.

The previous prime is 31861970249. The next prime is 31861970317. The reversal of 31861970281 is 18207916813.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31476437056 + 385533225 = 177416^2 + 19635^2 .

It is an emirp because it is prime and its reverse (18207916813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31861970281 - 2⁵ = 31861970249 is a prime.

It is a super-2 number, since 2×31861970281² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31861970981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15930985140 + 15930985141.

It is an arithmetic number, because the mean of its divisors is an integer number (15930985141).

Almost surely, 2^31861970281 is an apocalyptic number.

It is an amenable number.

31861970281 is a deficient number, since it is larger than the sum of its proper divisors (1).

31861970281 is an equidigital number, since it uses as much as digits as its factorization.

31861970281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 31861970281 in words is "thirty-one billion, eight hundred sixty-one million, nine hundred seventy thousand, two hundred eighty-one".