21180698880 has 288 divisors, whose sum is σ = 74817267840. Its totient is φ = 5063639040.

The previous prime is 21180698867. The next prime is 21180698887. The reversal of 21180698880 is 8889608112.

It is a happy number.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21180698887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3080086 + ... + 3086954.

It is an arithmetic number, because the mean of its divisors is an integer number (259782180).

Almost surely, 2^21180698880 is an apocalyptic number.

21180698880 is a gapful number since it is divisible by the number (20) 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 21180698880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37408633920).

21180698880 is an abundant number, since it is smaller than the sum of its proper divisors (53636568960).

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

21180698880 is a wasteful number, since it uses less digits than its factorization.

21180698880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6977 (or 6963 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 51.

The spelling of 21180698880 in words is "twenty-one billion, one hundred eighty million, six hundred ninety-eight thousand, eight hundred eighty".