31718587261 has 2 divisors, whose sum is σ = 31718587262. Its totient is φ = 31718587260.

The previous prime is 31718587237. The next prime is 31718587291. The reversal of 31718587261 is 16278581713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30474684900 + 1243902361 = 174570^2 + 35269^2 .

It is a cyclic number.

It is not a de Polignac number, because 31718587261 - 2⁷ = 31718587133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31718587231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15859293630 + 15859293631.

It is an arithmetic number, because the mean of its divisors is an integer number (15859293631).

Almost surely, 2^31718587261 is an apocalyptic number.

It is an amenable number.

31718587261 is a deficient number, since it is larger than the sum of its proper divisors (1).

31718587261 is an equidigital number, since it uses as much as digits as its factorization.

31718587261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 564480, while the sum is 49.

The spelling of 31718587261 in words is "thirty-one billion, seven hundred eighteen million, five hundred eighty-seven thousand, two hundred sixty-one".