21790433280 has 896 divisors, whose sum is σ = 90591436800. Its totient is φ = 4431544320.

The previous prime is 21790433267. The next prime is 21790433299. The reversal of 21790433280 is 8233409712.

It is a tau number, because it is divible by the number of its divisors (896).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 463626217 + ... + 463626263.

Almost surely, 2^21790433280 is an apocalyptic number.

21790433280 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 21790433280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45295718400).

21790433280 is an abundant number, since it is smaller than the sum of its proper divisors (68801003520).

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

21790433280 is an equidigital number, since it uses as much as digits as its factorization.

21790433280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The spelling of 21790433280 in words is "twenty-one billion, seven hundred ninety million, four hundred thirty-three thousand, two hundred eighty".