63639978 has 16 divisors (see below), whose sum is σ = 131669280. Its totient is φ = 20481776.

The previous prime is 63639971. The next prime is 63639997. The reversal of 63639978 is 87993636.

It is a happy number.

63639978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 63639978.

It is not an unprimeable number, because it can be changed into a prime (63639971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182700 + ... + 183047.

It is an arithmetic number, because the mean of its divisors is an integer number (8229330).

Almost surely, 2^63639978 is an apocalyptic number.

63639978 is an abundant number, since it is smaller than the sum of its proper divisors (68029302).

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

63639978 is a wasteful number, since it uses less digits than its factorization.

63639978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365781.

The product of its digits is 1469664, while the sum is 51.

The square root of 63639978 is about 7977.4668911880. The cubic root of 63639978 is about 399.2485433329.

The spelling of 63639978 in words is "sixty-three million, six hundred thirty-nine thousand, nine hundred seventy-eight".