63921781872 has 240 divisors, whose sum is σ = 205976691648. Its totient is φ = 18330624000.

The previous prime is 63921781849. The next prime is 63921781879. The reversal of 63921781872 is 27818712936.

It is a happy number.

63921781872 is a `hidden beast` number, since 6 + 392 + 1 + 78 + 187 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63921781879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3268122 + ... + 3287622.

Almost surely, 2^63921781872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 63921781872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102988345824).

63921781872 is an abundant number, since it is smaller than the sum of its proper divisors (142054909776).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

63921781872 is a wasteful number, since it uses less digits than its factorization.

63921781872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19648 (or 19639 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The spelling of 63921781872 in words is "sixty-three billion, nine hundred twenty-one million, seven hundred eighty-one thousand, eight hundred seventy-two".