12506226561 has 6 divisors (see below), whose sum is σ = 18064549490. Its totient is φ = 8337484368.

The previous prime is 12506226521. The next prime is 12506226581. The reversal of 12506226561 is 16562260521.

12506226561 is a `hidden beast` number, since 1 + 25 + 0 + 622 + 6 + 5 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11906956161 + 599270400 = 109119^2 + 24480^2 .

It is not a de Polignac number, because 12506226561 - 2⁹ = 12506226049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12506226521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 694790356 + ... + 694790373.

Almost surely, 2^12506226561 is an apocalyptic number.

It is an amenable number.

12506226561 is a deficient number, since it is larger than the sum of its proper divisors (5558322929).

12506226561 is a wasteful number, since it uses less digits than its factorization.

12506226561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389580735 (or 1389580732 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 12506226561 in words is "twelve billion, five hundred six million, two hundred twenty-six thousand, five hundred sixty-one".