12651387640 has 64 divisors (see below), whose sum is σ = 28986451200. Its totient is φ = 4968594432.

The previous prime is 12651387601. The next prime is 12651387653. The reversal of 12651387640 is 4678315621.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 641446 + ... + 660874.

It is an arithmetic number, because the mean of its divisors is an integer number (452913300).

Almost surely, 2^12651387640 is an apocalyptic number.

12651387640 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 12651387640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14493225600).

12651387640 is an abundant number, since it is smaller than the sum of its proper divisors (16335063560).

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

12651387640 is a wasteful number, since it uses less digits than its factorization.

12651387640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19736 (or 19732 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 43.

The spelling of 12651387640 in words is "twelve billion, six hundred fifty-one million, three hundred eighty-seven thousand, six hundred forty".