18388391869 has 4 divisors (see below), whose sum is σ = 18388736640. Its totient is φ = 18388047100.

The previous prime is 18388391863. The next prime is 18388391893. The reversal of 18388391869 is 96819388381.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18388391869 - 2²⁹ = 17851520957 is a prime.

It is a super-2 number, since 2×18388391869² (a number of 21 digits) contains 22 as substring.

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 18388391869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18388391863) 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, 73459 + ... + 205360.

It is an arithmetic number, because the mean of its divisors is an integer number (4597184160).

Almost surely, 2^18388391869 is an apocalyptic number.

It is an amenable number.

18388391869 is a deficient number, since it is larger than the sum of its proper divisors (344771).

18388391869 is an equidigital number, since it uses as much as digits as its factorization.

18388391869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344770.

The product of its digits is 17915904, while the sum is 64.

The spelling of 18388391869 in words is "eighteen billion, three hundred eighty-eight million, three hundred ninety-one thousand, eight hundred sixty-nine".