12640203521 has 8 divisors (see below), whose sum is σ = 13851151104. Its totient is φ = 11439562320.

The previous prime is 12640203509. The next prime is 12640203557. The reversal of 12640203521 is 12530204621.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12640203521 - 2²⁶ = 12573094657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12640203721) 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, 2574026 + ... + 2578931.

It is an arithmetic number, because the mean of its divisors is an integer number (1731393888).

Almost surely, 2^12640203521 is an apocalyptic number.

12640203521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12640203521 is a deficient number, since it is larger than the sum of its proper divisors (1210947583).

12640203521 is a wasteful number, since it uses less digits than its factorization.

12640203521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5153191.

The product of its (nonzero) digits is 2880, while the sum is 26.

The spelling of 12640203521 in words is "twelve billion, six hundred forty million, two hundred three thousand, five hundred twenty-one".