21678198288 has 80 divisors (see below), whose sum is σ = 56939837760. Its totient is φ = 7106050048.

The previous prime is 21678198281. The next prime is 21678198301. The reversal of 21678198288 is 88289187612.

It is a super-2 number, since 2×21678198288² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21678198281) 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 15 ways as a sum of consecutive naturals, for example, 688228 + ... + 719036.

It is an arithmetic number, because the mean of its divisors is an integer number (711747972).

Almost surely, 2^21678198288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21678198288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28469918880).

21678198288 is an abundant number, since it is smaller than the sum of its proper divisors (35261639472).

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

21678198288 is a wasteful number, since it uses less digits than its factorization.

21678198288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31064 (or 31058 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 60.

The spelling of 21678198288 in words is "twenty-one billion, six hundred seventy-eight million, one hundred ninety-eight thousand, two hundred eighty-eight".