31251344315209 has 2 divisors, whose sum is σ = 31251344315210. Its totient is φ = 31251344315208.

The previous prime is 31251344315201. The next prime is 31251344315263. The reversal of 31251344315209 is 90251344315213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28527349210000 + 2723995105209 = 5341100^2 + 1650453^2 .

It is a cyclic number.

It is not a de Polignac number, because 31251344315209 - 2³ = 31251344315201 is a prime.

It is a super-2 number, since 2×31251344315209² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31251344315201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15625672157604 + 15625672157605.

It is an arithmetic number, because the mean of its divisors is an integer number (15625672157605).

Almost surely, 2^{31251344315209} is an apocalyptic number.

It is an amenable number.

31251344315209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31251344315209 is an equidigital number, since it uses as much as digits as its factorization.

31251344315209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 388800, while the sum is 43.

The spelling of 31251344315209 in words is "thirty-one trillion, two hundred fifty-one billion, three hundred forty-four million, three hundred fifteen thousand, two hundred nine".