18399807478 has 32 divisors (see below), whose sum is σ = 30956143680. Its totient is φ = 8146293120.

The previous prime is 18399807473. The next prime is 18399807479. The reversal of 18399807478 is 87470899381.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18399807473) 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 in 15 ways as a sum of consecutive naturals, for example, 66393 + ... + 202996.

It is an arithmetic number, because the mean of its divisors is an integer number (967379490).

Almost surely, 2^18399807478 is an apocalyptic number.

18399807478 is a deficient number, since it is larger than the sum of its proper divisors (12556336202).

18399807478 is a wasteful number, since it uses less digits than its factorization.

18399807478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269512.

The product of its (nonzero) digits is 24385536, while the sum is 64.

The spelling of 18399807478 in words is "eighteen billion, three hundred ninety-nine million, eight hundred seven thousand, four hundred seventy-eight".