31347875281 has 2 divisors, whose sum is σ = 31347875282. Its totient is φ = 31347875280.

The previous prime is 31347875257. The next prime is 31347875327. The reversal of 31347875281 is 18257874313.

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., 16801344400 + 14546530881 = 129620^2 + 120609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31347875281 is a prime.

It is a super-2 number, since 2×31347875281² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31347875681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15673937640 + 15673937641.

It is an arithmetic number, because the mean of its divisors is an integer number (15673937641).

Almost surely, 2^31347875281 is an apocalyptic number.

It is an amenable number.

31347875281 is a deficient number, since it is larger than the sum of its proper divisors (1).

31347875281 is an equidigital number, since it uses as much as digits as its factorization.

31347875281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1128960, while the sum is 49.

The spelling of 31347875281 in words is "thirty-one billion, three hundred forty-seven million, eight hundred seventy-five thousand, two hundred eighty-one".