12778415745481 has 9 divisors (see below), whose sum is σ = 13024260130791. Its totient is φ = 12537127677672.

The previous prime is 12778415745467. The next prime is 12778415745517. The reversal of 12778415745481 is 18454751487721.

The square root of 12778415745481 is 3574691.

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., 9211923063225 + 3566492682256 = 3035115^2 + 1888516^2 .

It is not a de Polignac number, because 12778415745481 - 2⁵ = 12778415745449 is a prime.

It is a super-2 number, since 2×12778415745481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12778415743481) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 189424900 + ... + 189492346.

Almost surely, 2^{12778415745481} is an apocalyptic number.

12778415745481 is the 3574691-st square number.

12778415745481 is the 1787346-th centered octagonal number.

It is an amenable number.

12778415745481 is a deficient number, since it is larger than the sum of its proper divisors (245844385310).

12778415745481 is an frugal number, since it uses more digits than its factorization.

12778415745481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135000 (or 67500 counting only the distinct ones).

The product of its digits is 70246400, while the sum is 64.

Multiplying 12778415745481 by its sum of digits (64), we get a square (817818607710784 = 28597528²).

The spelling of 12778415745481 in words is "twelve trillion, seven hundred seventy-eight billion, four hundred fifteen million, seven hundred forty-five thousand, four hundred eighty-one".