21617894480 has 480 divisors, whose sum is σ = 67326940800. Its totient is φ = 6379720704.

The previous prime is 21617894471. The next prime is 21617894483. The reversal of 21617894480 is 8449871612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21617894483) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 80363786 + ... + 80364054.

It is an arithmetic number, because the mean of its divisors is an integer number (140264460).

Almost surely, 2^21617894480 is an apocalyptic number.

21617894480 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 21617894480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33663470400).

21617894480 is an abundant number, since it is smaller than the sum of its proper divisors (45709046320).

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

21617894480 is a wasteful number, since it uses less digits than its factorization.

21617894480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 50.

The spelling of 21617894480 in words is "twenty-one billion, six hundred seventeen million, eight hundred ninety-four thousand, four hundred eighty".