63999618 has 32 divisors (see below), whose sum is σ = 131825664. Its totient is φ = 20703312.

The previous prime is 63999599. The next prime is 63999641. The reversal of 63999618 is 81699936.

It is a super-2 number, since 2×63999618² = 8191902208291848, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34921 + ... + 36707.

It is an arithmetic number, because the mean of its divisors is an integer number (4119552).

Almost surely, 2^63999618 is an apocalyptic number.

63999618 is an abundant number, since it is smaller than the sum of its proper divisors (67826046).

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

63999618 is a wasteful number, since it uses less digits than its factorization.

63999618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1966.

The product of its digits is 629856, while the sum is 51.

The square root of 63999618 is about 7999.9761249644. The cubic root of 63999618 is about 399.9992041651. Note that the first 3 decimals are identical.

The spelling of 63999618 in words is "sixty-three million, nine hundred ninety-nine thousand, six hundred eighteen".