63978909021 has 16 divisors (see below), whose sum is σ = 94807765120. Its totient is φ = 42641717760.

The previous prime is 63978908993. The next prime is 63978909037. The reversal of 63978909021 is 12090987936.

It is not a de Polignac number, because 63978909021 - 2¹¹ = 63978906973 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 (63978904021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194020 + ... + 406941.

It is an arithmetic number, because the mean of its divisors is an integer number (5925485320).

Almost surely, 2^63978909021 is an apocalyptic number.

It is an amenable number.

63978909021 is a deficient number, since it is larger than the sum of its proper divisors (30828856099).

63978909021 is a wasteful number, since it uses less digits than its factorization.

63978909021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604913 (or 604907 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 63978909021 in words is "sixty-three billion, nine hundred seventy-eight million, nine hundred nine thousand, twenty-one".