12640436421 has 8 divisors (see below), whose sum is σ = 16855279104. Its totient is φ = 8426275680.

The previous prime is 12640436401. The next prime is 12640436423. The reversal of 12640436421 is 12463404621.

It is a happy number.

12640436421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 12640436421 - 2²⁷ = 12506218693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640436423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125541 + ... + 202586.

It is an arithmetic number, because the mean of its divisors is an integer number (2106909888).

Almost surely, 2^12640436421 is an apocalyptic number.

It is an amenable number.

12640436421 is a deficient number, since it is larger than the sum of its proper divisors (4214842683).

12640436421 is a wasteful number, since it uses less digits than its factorization.

12640436421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340971.

The product of its (nonzero) digits is 27648, while the sum is 33.

The spelling of 12640436421 in words is "twelve billion, six hundred forty million, four hundred thirty-six thousand, four hundred twenty-one".