1315356521861 has 2 divisors, whose sum is σ = 1315356521862. Its totient is φ = 1315356521860.

The previous prime is 1315356521849. The next prime is 1315356521887. The reversal of 1315356521861 is 1681256535131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1244549972836 + 70806549025 = 1115594^2 + 266095^2 .

It is a cyclic number.

It is not a de Polignac number, because 1315356521861 - 2¹⁸ = 1315356259717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1315356521891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 657678260930 + 657678260931.

It is an arithmetic number, because the mean of its divisors is an integer number (657678260931).

Almost surely, 2^{1315356521861} is an apocalyptic number.

It is an amenable number.

1315356521861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1315356521861 is an equidigital number, since it uses as much as digits as its factorization.

1315356521861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648000, while the sum is 47.

The spelling of 1315356521861 in words is "one trillion, three hundred fifteen billion, three hundred fifty-six million, five hundred twenty-one thousand, eight hundred sixty-one".