12640404551 has 4 divisors (see below), whose sum is σ = 13076280600. Its totient is φ = 12204528504.

The previous prime is 12640404503. The next prime is 12640404577. The reversal of 12640404551 is 15540404621.

12640404551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12640404551 - 2²² = 12636210247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640454551) 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 3 ways as a sum of consecutive naturals, for example, 217937981 + ... + 217938038.

It is an arithmetic number, because the mean of its divisors is an integer number (3269070150).

Almost surely, 2^12640404551 is an apocalyptic number.

12640404551 is a deficient number, since it is larger than the sum of its proper divisors (435876049).

12640404551 is an equidigital number, since it uses as much as digits as its factorization.

12640404551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435876048.

The product of its (nonzero) digits is 19200, while the sum is 32.

The spelling of 12640404551 in words is "twelve billion, six hundred forty million, four hundred four thousand, five hundred fifty-one".