78000663643 has 4 divisors (see below), whose sum is σ = 89143615600. Its totient is φ = 66857711688.

The previous prime is 78000663599. The next prime is 78000663679. The reversal of 78000663643 is 34636600087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34636600087 = 1399 ⋅24758113.

It is a cyclic number.

It is not a de Polignac number, because 78000663643 - 2²¹ = 77998566491 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78000663643.

It is not an unprimeable number, because it can be changed into a prime (78000663043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5571475968 + ... + 5571475981.

It is an arithmetic number, because the mean of its divisors is an integer number (22285903900).

Almost surely, 2^78000663643 is an apocalyptic number.

78000663643 is a deficient number, since it is larger than the sum of its proper divisors (11142951957).

78000663643 is a wasteful number, since it uses less digits than its factorization.

78000663643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11142951956.

The product of its (nonzero) digits is 435456, while the sum is 43.

The spelling of 78000663643 in words is "seventy-eight billion, six hundred sixty-three thousand, six hundred forty-three".