63866221 has 2 divisors, whose sum is σ = 63866222. Its totient is φ = 63866220.

The previous prime is 63866213. The next prime is 63866227. The reversal of 63866221 is 12266836.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61936900 + 1929321 = 7870^2 + 1389^2 .

It is a cyclic number.

It is not a de Polignac number, because 63866221 - 2³ = 63866213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63866227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31933110 + 31933111.

It is an arithmetic number, because the mean of its divisors is an integer number (31933111).

Almost surely, 2^63866221 is an apocalyptic number.

It is an amenable number.

63866221 is a deficient number, since it is larger than the sum of its proper divisors (1).

63866221 is an equidigital number, since it uses as much as digits as its factorization.

63866221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 34.

The square root of 63866221 is about 7991.6344385864. The cubic root of 63866221 is about 399.7210993312.

The spelling of 63866221 in words is "sixty-three million, eight hundred sixty-six thousand, two hundred twenty-one".