813963647 has 12 divisors (see below), whose sum is σ = 947367360. Its totient is φ = 697306176.

The previous prime is 813963643. The next prime is 813963649. The reversal of 813963647 is 746369318.

It is a happy number.

It is not a de Polignac number, because 813963647 - 2² = 813963643 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 (813963643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 124658 + ... + 131024.

It is an arithmetic number, because the mean of its divisors is an integer number (78947280).

Almost surely, 2^813963647 is an apocalyptic number.

813963647 is a deficient number, since it is larger than the sum of its proper divisors (133403713).

813963647 is a wasteful number, since it uses less digits than its factorization.

813963647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8990 (or 8983 counting only the distinct ones).

The product of its digits is 653184, while the sum is 47.

The square root of 813963647 is about 28530.0481422657. The cubic root of 813963647 is about 933.6877688575.

The spelling of 813963647 in words is "eight hundred thirteen million, nine hundred sixty-three thousand, six hundred forty-seven".