12657609991 has 4 divisors (see below), whose sum is σ = 13631272312. Its totient is φ = 11683947672.

The previous prime is 12657609977. The next prime is 12657610001. The reversal of 12657609991 is 19990675621.

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 12657609991 - 2⁵ = 12657609959 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 (12657609691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 486831141 + ... + 486831166.

It is an arithmetic number, because the mean of its divisors is an integer number (3407818078).

Almost surely, 2^12657609991 is an apocalyptic number.

12657609991 is a deficient number, since it is larger than the sum of its proper divisors (973662321).

12657609991 is an equidigital number, since it uses as much as digits as its factorization.

12657609991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973662320.

The product of its (nonzero) digits is 1837080, while the sum is 55.

The spelling of 12657609991 in words is "twelve billion, six hundred fifty-seven million, six hundred nine thousand, nine hundred ninety-one".