12505655538 has 12 divisors (see below), whose sum is σ = 27095587038. Its totient is φ = 4168551840.

The previous prime is 12505655531. The next prime is 12505655627. The reversal of 12505655538 is 83555650521.

It is a happy number.

12505655538 is a `hidden beast` number, since 1 + 2 + 5 + 0 + 565 + 55 + 38 = 666.

12505655538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 10521220329 + 1984435209 = 102573^2 + 44547^2 .

It is a super-2 number, since 2×12505655538² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12505655493 and 12505655502.

It is not an unprimeable number, because it can be changed into a prime (12505655531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 347379303 + ... + 347379338.

Almost surely, 2^12505655538 is an apocalyptic number.

12505655538 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12505655538 is an abundant number, since it is smaller than the sum of its proper divisors (14589931500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12505655538 is a wasteful number, since it uses less digits than its factorization.

12505655538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694758649 (or 694758646 counting only the distinct ones).

The product of its (nonzero) digits is 900000, while the sum is 45.

The spelling of 12505655538 in words is "twelve billion, five hundred five million, six hundred fifty-five thousand, five hundred thirty-eight".