1265256525621 has 24 divisors (see below), whose sum is σ = 1860239846080. Its totient is φ = 764372157120.

The previous prime is 1265256525613. The next prime is 1265256525641.

It is a happy number.

1265256525621 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1265256525621 - 2³ = 1265256525613 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265256525641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5454361 + ... + 5681598.

Almost surely, 2^{1265256525621} is an apocalyptic number.

1265256525621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1265256525621 is a deficient number, since it is larger than the sum of its proper divisors (594983320459).

1265256525621 is a wasteful number, since it uses less digits than its factorization.

1265256525621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11136297 (or 11136286 counting only the distinct ones).

The product of its digits is 2160000, while the sum is 48.

The spelling of 1265256525621 in words is "one trillion, two hundred sixty-five billion, two hundred fifty-six million, five hundred twenty-five thousand, six hundred twenty-one".