12647561820 has 96 divisors (see below), whose sum is σ = 36292451328. Its totient is φ = 3289443072.

The previous prime is 12647561779. The next prime is 12647561833. The reversal of 12647561820 is 2816574621.

It is a happy number.

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, 818607 + ... + 833913.

It is an arithmetic number, because the mean of its divisors is an integer number (378046368).

Almost surely, 2^12647561820 is an apocalyptic number.

12647561820 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 12647561820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18146225664).

12647561820 is an abundant number, since it is smaller than the sum of its proper divisors (23644889508).

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

12647561820 is a wasteful number, since it uses less digits than its factorization.

12647561820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15659 (or 15657 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 42.

The spelling of 12647561820 in words is "twelve billion, six hundred forty-seven million, five hundred sixty-one thousand, eight hundred twenty".