63956519921 has 8 divisors (see below), whose sum is σ = 73267615680. Its totient is φ = 54689036688.

The previous prime is 63956519909. The next prime is 63956519929. The reversal of 63956519921 is 12991565936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 63956519921 - 2⁶ = 63956519857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (63956519929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10899986 + ... + 10905851.

It is an arithmetic number, because the mean of its divisors is an integer number (9158451960).

Almost surely, 2^63956519921 is an apocalyptic number.

It is an amenable number.

63956519921 is a deficient number, since it is larger than the sum of its proper divisors (9311095759).

63956519921 is a wasteful number, since it uses less digits than its factorization.

63956519921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21806263.

The product of its digits is 3936600, while the sum is 56.

The spelling of 63956519921 in words is "sixty-three billion, nine hundred fifty-six million, five hundred nineteen thousand, nine hundred twenty-one".