63638821 has 2 divisors, whose sum is σ = 63638822. Its totient is φ = 63638820.

The previous prime is 63638819. The next prime is 63638831. The reversal of 63638821 is 12883636.

63638821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53494596 + 10144225 = 7314^2 + 3185^2 .

It is a cyclic number.

It is not a de Polignac number, because 63638821 - 2¹ = 63638819 is a prime.

Together with 63638819, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63638801) 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 as a sum of consecutive naturals, namely, 31819410 + 31819411.

It is an arithmetic number, because the mean of its divisors is an integer number (31819411).

Almost surely, 2^63638821 is an apocalyptic number.

It is an amenable number.

63638821 is a deficient number, since it is larger than the sum of its proper divisors (1).

63638821 is an equidigital number, since it uses as much as digits as its factorization.

63638821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 37.

The square root of 63638821 is about 7977.3943741049. The cubic root of 63638821 is about 399.2461238194.

The spelling of 63638821 in words is "sixty-three million, six hundred thirty-eight thousand, eight hundred twenty-one".