21798399168 has 168 divisors, whose sum is σ = 76900093088. Its totient is φ = 5749014528.

The previous prime is 21798399163. The next prime is 21798399179. The reversal of 21798399168 is 86199389712.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21798399163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 155521 + ... + 260352.

Almost surely, 2^21798399168 is an apocalyptic number.

21798399168 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21798399168 is an abundant number, since it is smaller than the sum of its proper divisors (55101693920).

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

21798399168 is a wasteful number, since it uses less digits than its factorization.

21798399168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415911 (or 415898 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 63.

The spelling of 21798399168 in words is "twenty-one billion, seven hundred ninety-eight million, three hundred ninety-nine thousand, one hundred sixty-eight".