21794554656 has 480 divisors, whose sum is σ = 77747281920. Its totient is φ = 5850662400.

The previous prime is 21794554651. The next prime is 21794554669. The reversal of 21794554656 is 65645549712.

21794554656 is a `hidden beast` number, since 2 + 1 + 7 + 9 + 45 + 546 + 56 = 666.

It is a super-2 number, since 2×21794554656² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21794554651) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 65844411 + ... + 65844741.

It is an arithmetic number, because the mean of its divisors is an integer number (161973504).

Almost surely, 2^21794554656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21794554656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38873640960).

21794554656 is an abundant number, since it is smaller than the sum of its proper divisors (55952727264).

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

21794554656 is a wasteful number, since it uses less digits than its factorization.

21794554656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570 (or 553 counting only the distinct ones).

The product of its digits is 9072000, while the sum is 54.

The spelling of 21794554656 in words is "twenty-one billion, seven hundred ninety-four million, five hundred fifty-four thousand, six hundred fifty-six".