21818363819 has 12 divisors (see below), whose sum is σ = 25407571248. Its totient is φ = 18681541200.

The previous prime is 21818363779. The next prime is 21818363821. The reversal of 21818363819 is 91836381812.

It is not a de Polignac number, because 21818363819 - 2⁸ = 21818363563 is a prime.

It is a super-2 number, since 2×21818363819² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21818363849) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190487 + ... + 282704.

It is an arithmetic number, because the mean of its divisors is an integer number (2117297604).

Almost surely, 2^21818363819 is an apocalyptic number.

21818363819 is a deficient number, since it is larger than the sum of its proper divisors (3589207429).

21818363819 is an equidigital number, since it uses as much as digits as its factorization.

21818363819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474146 (or 474139 counting only the distinct ones).

The product of its digits is 497664, while the sum is 50.

The spelling of 21818363819 in words is "twenty-one billion, eight hundred eighteen million, three hundred sixty-three thousand, eight hundred nineteen".