1313564121557 has 4 divisors (see below), whose sum is σ = 1314327379596. Its totient is φ = 1312800863520.

The previous prime is 1313564121539. The next prime is 1313564121613. The reversal of 1313564121557 is 7551214653131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 510244490596 + 803319630961 = 714314^2 + 896281^2 .

It is a cyclic number.

It is not a de Polignac number, because 1313564121557 - 2¹² = 1313564117461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313564121757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 381626438 + ... + 381629879.

It is an arithmetic number, because the mean of its divisors is an integer number (328581844899).

Almost surely, 2^{1313564121557} is an apocalyptic number.

It is an amenable number.

1313564121557 is a deficient number, since it is larger than the sum of its proper divisors (763258039).

1313564121557 is an equidigital number, since it uses as much as digits as its factorization.

1313564121557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 763258038.

The product of its digits is 378000, while the sum is 44.

Adding to 1313564121557 its reverse (7551214653131), we get a palindrome (8864778774688).

The spelling of 1313564121557 in words is "one trillion, three hundred thirteen billion, five hundred sixty-four million, one hundred twenty-one thousand, five hundred fifty-seven".