1261715717057 has 4 divisors (see below), whose sum is σ = 1261748721540. Its totient is φ = 1261682712576.

The previous prime is 1261715717021. The next prime is 1261715717071. The reversal of 1261715717057 is 7507175171621.

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 544118670736 + 717597046321 = 737644^2 + 847111^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261715717057 - 2¹⁰ = 1261715716033 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1261715716996 and 1261715717014.

It is not an unprimeable number, because it can be changed into a prime (1261715711057) 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, 16444832 + ... + 16521377.

It is an arithmetic number, because the mean of its divisors is an integer number (315437180385).

Almost surely, 2^{1261715717057} is an apocalyptic number.

It is an amenable number.

1261715717057 is a deficient number, since it is larger than the sum of its proper divisors (33004483).

1261715717057 is an equidigital number, since it uses as much as digits as its factorization.

1261715717057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33004482.

The product of its (nonzero) digits is 720300, while the sum is 50.

The spelling of 1261715717057 in words is "one trillion, two hundred sixty-one billion, seven hundred fifteen million, seven hundred seventeen thousand, fifty-seven".