6636397647 has 32 divisors (see below), whose sum is σ = 9904029696. Its totient is φ = 3917944800.

The previous prime is 6636397631. The next prime is 6636397657. The reversal of 6636397647 is 7467936366.

It is not a de Polignac number, because 6636397647 - 2⁴ = 6636397631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6636397657) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 537372 + ... + 549582.

It is an arithmetic number, because the mean of its divisors is an integer number (309500928).

Almost surely, 2^6636397647 is an apocalyptic number.

6636397647 is a deficient number, since it is larger than the sum of its proper divisors (3267632049).

6636397647 is a wasteful number, since it uses less digits than its factorization.

6636397647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12651.

The product of its digits is 20575296, while the sum is 57.

The square root of 6636397647 is about 81464.0880818045. The cubic root of 6636397647 is about 1879.2193120987.

The spelling of 6636397647 in words is "six billion, six hundred thirty-six million, three hundred ninety-seven thousand, six hundred forty-seven".