21304745280 has 1120 divisors, whose sum is σ = 95619417600. Its totient is φ = 4438167552.

The previous prime is 21304745269. The next prime is 21304745309. The reversal of 21304745280 is 8254740312.

It is a happy number.

21304745280 is a `hidden beast` number, since 2 + 1 + 304 + 74 + 5 + 280 = 666.

It is a tau number, because it is divible by the number of its divisors (1120).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 269680281 + ... + 269680359.

It is an arithmetic number, because the mean of its divisors is an integer number (85374480).

Almost surely, 2^21304745280 is an apocalyptic number.

21304745280 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 21304745280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47809708800).

21304745280 is an abundant number, since it is smaller than the sum of its proper divisors (74314672320).

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

21304745280 is an equidigital number, since it uses as much as digits as its factorization.

21304745280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The spelling of 21304745280 in words is "twenty-one billion, three hundred four million, seven hundred forty-five thousand, two hundred eighty".