12640403636 has 24 divisors (see below), whose sum is σ = 26096318976. Its totient is φ = 5242563360.

The previous prime is 12640403603. The next prime is 12640403639. The reversal of 12640403636 is 63630404621.

It is a junction number, because it is equal to n+sod(n) for n = 12640403596 and 12640403605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640403639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7280471 + ... + 7282206.

It is an arithmetic number, because the mean of its divisors is an integer number (1087346624).

Almost surely, 2^12640403636 is an apocalyptic number.

It is an amenable number.

12640403636 is an abundant number, since it is smaller than the sum of its proper divisors (13455915340).

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

12640403636 is a wasteful number, since it uses less digits than its factorization.

12640403636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14562719 (or 14562717 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 35.

The spelling of 12640403636 in words is "twelve billion, six hundred forty million, four hundred three thousand, six hundred thirty-six".