12775541855521 has 27 divisors (see below), whose sum is σ = 13226410609587. Its totient is φ = 12339875343600.

The previous prime is 12775541855519. The next prime is 12775541855569. The reversal of 12775541855521 is 12555814557721.

The square root of 12775541855521 is 3574289.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 12274589327121 + 500952528400 = 3503511^2 + 707780^2 .

It is not a de Polignac number, because 12775541855521 - 2¹ = 12775541855519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12775541855821) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 15523136716 + ... + 15523137538.

Almost surely, 2^{12775541855521} is an apocalyptic number.

12775541855521 is the 3574289-th square number.

12775541855521 is the 1787145-th centered octagonal number.

It is an amenable number.

12775541855521 is a deficient number, since it is larger than the sum of its proper divisors (450868754066).

12775541855521 is an frugal number, since it uses more digits than its factorization.

12775541855521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1934 (or 967 counting only the distinct ones).

The product of its digits is 19600000, while the sum is 58.

The spelling of 12775541855521 in words is "twelve trillion, seven hundred seventy-five billion, five hundred forty-one million, eight hundred fifty-five thousand, five hundred twenty-one".