18399807499 has 4 divisors (see below), whose sum is σ = 19368218440. Its totient is φ = 17431396560.

The previous prime is 18399807479. The next prime is 18399807527. The reversal of 18399807499 is 99470899381.

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 18399807499 - 2¹¹ = 18399805451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18399807449) 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, 484205442 + ... + 484205479.

It is an arithmetic number, because the mean of its divisors is an integer number (4842054610).

Almost surely, 2^18399807499 is an apocalyptic number.

18399807499 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18399807499 is a deficient number, since it is larger than the sum of its proper divisors (968410941).

18399807499 is an equidigital number, since it uses as much as digits as its factorization.

18399807499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968410940.

The product of its (nonzero) digits is 35271936, while the sum is 67.

The spelling of 18399807499 in words is "eighteen billion, three hundred ninety-nine million, eight hundred seven thousand, four hundred ninety-nine".