63999999999999 has 96 divisors (see below), whose sum is σ = 107793392844800. Its totient is φ = 35835610510656.

The previous prime is 63999999999997. The next prime is 64000000000007. The reversal of 63999999999999 is 99999999999936.

It is a Cunningham number, because it is equal to 200⁶-1.

It is not a de Polignac number, because 63999999999999 - 2¹ = 63999999999997 is a prime.

It is a super-9 number, since 9×63999999999999⁹ (a number of 126 digits) contains 999999999 as substring.

It is a Duffinian number.

63999999999999 is a modest number, since divided by 9999999 gives 6399999 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 63999999999891 and 63999999999900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63999999999997) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4823992764 + ... + 4824006030.

Almost surely, 2^{63999999999999} is an apocalyptic number.

63999999999999 is a deficient number, since it is larger than the sum of its proper divisors (43793392844801).

63999999999999 is a wasteful number, since it uses less digits than its factorization.

63999999999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19289 (or 19286 counting only the distinct ones).

The product of its digits is 5083731656658, while the sum is 117.

The spelling of 63999999999999 in words is "sixty-three trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".