12640664949 has 16 divisors (see below), whose sum is σ = 18414609984. Its totient is φ = 7649264000.

The previous prime is 12640664923. The next prime is 12640664951. The reversal of 12640664949 is 94946604621.

It is a cyclic number.

It is not a de Polignac number, because 12640664949 - 2⁹ = 12640664437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640664909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 271752 + ... + 314849.

It is an arithmetic number, because the mean of its divisors is an integer number (1150913124).

Almost surely, 2^12640664949 is an apocalyptic number.

It is an amenable number.

12640664949 is a deficient number, since it is larger than the sum of its proper divisors (5773945035).

12640664949 is a wasteful number, since it uses less digits than its factorization.

12640664949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 587268.

The product of its (nonzero) digits is 2239488, while the sum is 51.

The spelling of 12640664949 in words is "twelve billion, six hundred forty million, six hundred sixty-four thousand, nine hundred forty-nine".