21188321280 has 1344 divisors, whose sum is σ = 96819598080. Its totient is φ = 4359979008.

The previous prime is 21188321279. The next prime is 21188321281. The reversal of 21188321280 is 8212388112.

It is an interprime number because it is at equal distance from previous prime (21188321279) and next prime (21188321281).

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21188321281) 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 95 ways as a sum of consecutive naturals, for example, 921231349 + ... + 921231371.

Almost surely, 2^21188321280 is an apocalyptic number.

21188321280 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 21188321280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48409799040).

21188321280 is an abundant number, since it is smaller than the sum of its proper divisors (75631276800).

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

21188321280 is a wasteful number, since it uses less digits than its factorization.

21188321280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The spelling of 21188321280 in words is "twenty-one billion, one hundred eighty-eight million, three hundred twenty-one thousand, two hundred eighty".