18220821696 has 420 divisors, whose sum is σ = 68552924616. Its totient is φ = 4731955200.

The previous prime is 18220821691. The next prime is 18220821719. The reversal of 18220821696 is 69612802281.

It is not an unprimeable number, because it can be changed into a prime (18220821691) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2790916 + ... + 2797436.

Almost surely, 2^18220821696 is an apocalyptic number.

18220821696 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18220821696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34276462308).

18220821696 is an abundant number, since it is smaller than the sum of its proper divisors (50332102920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18220821696 is a wasteful number, since it uses less digits than its factorization.

18220821696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6570 (or 6544 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 18220821696 in words is "eighteen billion, two hundred twenty million, eight hundred twenty-one thousand, six hundred ninety-six".