63855551 has 2 divisors, whose sum is σ = 63855552. Its totient is φ = 63855550.

The previous prime is 63855503. The next prime is 63855643. The reversal of 63855551 is 15555836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 63855551 - 2¹⁸ = 63593407 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63855251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31927775 + 31927776.

It is an arithmetic number, because the mean of its divisors is an integer number (31927776).

Almost surely, 2^63855551 is an apocalyptic number.

63855551 is a deficient number, since it is larger than the sum of its proper divisors (1).

63855551 is an equidigital number, since it uses as much as digits as its factorization.

63855551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90000, while the sum is 38.

The square root of 63855551 is about 7990.9668376236. The cubic root of 63855551 is about 399.6988378937.

The spelling of 63855551 in words is "sixty-three million, eight hundred fifty-five thousand, five hundred fifty-one".