63881999 has 4 divisors (see below), whose sum is σ = 63899040. Its totient is φ = 63864960.

The previous prime is 63881981. The next prime is 63882011. The reversal of 63881999 is 99918836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 63881999 - 2¹⁶ = 63816463 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 63881999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63881299) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167 + ... + 11304.

It is an arithmetic number, because the mean of its divisors is an integer number (15974760).

Almost surely, 2^63881999 is an apocalyptic number.

63881999 is a deficient number, since it is larger than the sum of its proper divisors (17041).

63881999 is a wasteful number, since it uses less digits than its factorization.

63881999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17040.

The product of its digits is 839808, while the sum is 53.

The square root of 63881999 is about 7992.6215348908. The cubic root of 63881999 is about 399.7540133408.

The spelling of 63881999 in words is "sixty-three million, eight hundred eighty-one thousand, nine hundred ninety-nine".