12661225560 has 128 divisors (see below), whose sum is σ = 42614208000. Its totient is φ = 3343517568.

The previous prime is 12661225543. The next prime is 12661225573. The reversal of 12661225560 is 6552216621.

12661225560 is a `hidden beast` number, since 1 + 2 + 66 + 12 + 25 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54331 + ... + 168149.

It is an arithmetic number, because the mean of its divisors is an integer number (332923500).

Almost surely, 2^12661225560 is an apocalyptic number.

12661225560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12661225560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21307104000).

12661225560 is an abundant number, since it is smaller than the sum of its proper divisors (29952982440).

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

12661225560 is a wasteful number, since it uses less digits than its factorization.

12661225560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113942 (or 113932 counting only the distinct ones).

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

The spelling of 12661225560 in words is "twelve billion, six hundred sixty-one million, two hundred twenty-five thousand, five hundred sixty".