31661387043449 has 2 divisors, whose sum is σ = 31661387043450. Its totient is φ = 31661387043448.

The previous prime is 31661387043443. The next prime is 31661387043463. The reversal of 31661387043449 is 94434078316613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21993286090000 + 9668100953449 = 4689700^2 + 3109357^2 .

It is a cyclic number.

It is not a de Polignac number, because 31661387043449 - 2¹² = 31661387039353 is a prime.

It is not a weakly prime, because it can be changed into another prime (31661387043443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15830693521724 + 15830693521725.

It is an arithmetic number, because the mean of its divisors is an integer number (15830693521725).

Almost surely, 2^{31661387043449} is an apocalyptic number.

It is an amenable number.

31661387043449 is a deficient number, since it is larger than the sum of its proper divisors (1).

31661387043449 is an equidigital number, since it uses as much as digits as its factorization.

31661387043449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31352832, while the sum is 59.

The spelling of 31661387043449 in words is "thirty-one trillion, six hundred sixty-one billion, three hundred eighty-seven million, forty-three thousand, four hundred forty-nine".