663969847 has 4 divisors (see below), whose sum is σ = 681915016. Its totient is φ = 646024680.

The previous prime is 663969829. The next prime is 663969851. The reversal of 663969847 is 748969366.

663969847 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 748969366 = 2 ⋅374484683.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663969847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 663969791 and 663969800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663969857) 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, 8972529 + ... + 8972602.

It is an arithmetic number, because the mean of its divisors is an integer number (170478754).

Almost surely, 2^663969847 is an apocalyptic number.

663969847 is a deficient number, since it is larger than the sum of its proper divisors (17945169).

663969847 is a wasteful number, since it uses less digits than its factorization.

663969847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17945168.

The product of its digits is 11757312, while the sum is 58.

The square root of 663969847 is about 25767.6123651378. The cubic root of 663969847 is about 872.4009283163.

The spelling of 663969847 in words is "six hundred sixty-three million, nine hundred sixty-nine thousand, eight hundred forty-seven".