63976665997 has 4 divisors (see below), whose sum is σ = 65705765116. Its totient is φ = 62247566880.

The previous prime is 63976665943. The next prime is 63976666003. The reversal of 63976665997 is 79956667936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36493989156 + 27482676841 = 191034^2 + 165779^2 .

It is a cyclic number.

It is not a de Polignac number, because 63976665997 - 2⁷ = 63976665869 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 (63976665497) 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, 864549504 + ... + 864549577.

It is an arithmetic number, because the mean of its divisors is an integer number (16426441279).

Almost surely, 2^63976665997 is an apocalyptic number.

It is an amenable number.

63976665997 is a deficient number, since it is larger than the sum of its proper divisors (1729099119).

63976665997 is a wasteful number, since it uses less digits than its factorization.

63976665997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1729099118.

The product of its digits is 694416240, while the sum is 73.

The spelling of 63976665997 in words is "sixty-three billion, nine hundred seventy-six million, six hundred sixty-five thousand, nine hundred ninety-seven".