18821030399 has 4 divisors (see below), whose sum is σ = 18821564136. Its totient is φ = 18820496664.

The previous prime is 18821030329. The next prime is 18821030401. The reversal of 18821030399 is 99303012881.

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 18821030399 - 2¹⁶ = 18820964863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821030329) 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, 209924 + ... + 285849.

It is an arithmetic number, because the mean of its divisors is an integer number (4705391034).

Almost surely, 2^18821030399 is an apocalyptic number.

18821030399 is a deficient number, since it is larger than the sum of its proper divisors (533737).

18821030399 is an equidigital number, since it uses as much as digits as its factorization.

18821030399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533736.

The product of its (nonzero) digits is 93312, while the sum is 44.

The spelling of 18821030399 in words is "eighteen billion, eight hundred twenty-one million, thirty thousand, three hundred ninety-nine".