1265707061557 has 4 divisors (see below), whose sum is σ = 1299915360556. Its totient is φ = 1231498762560.

The previous prime is 1265707061539. The next prime is 1265707061569. The reversal of 1265707061557 is 7551607075621.

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 752658618481 + 513048443076 = 867559^2 + 716274^2 .

It is a cyclic number.

It is not a de Polignac number, because 1265707061557 - 2²³ = 1265698672949 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 (1265707161557) 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, 17104149444 + ... + 17104149517.

It is an arithmetic number, because the mean of its divisors is an integer number (324978840139).

Almost surely, 2^{1265707061557} is an apocalyptic number.

It is an amenable number.

1265707061557 is a deficient number, since it is larger than the sum of its proper divisors (34208298999).

1265707061557 is an equidigital number, since it uses as much as digits as its factorization.

1265707061557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34208298998.

The product of its (nonzero) digits is 3087000, while the sum is 52.

The spelling of 1265707061557 in words is "one trillion, two hundred sixty-five billion, seven hundred seven million, sixty-one thousand, five hundred fifty-seven".