21897229697280 has 1296 divisors, whose sum is σ = 89931490608960. Its totient is φ = 4903682015232.

The previous prime is 21897229697197. The next prime is 21897229697281. The reversal of 21897229697280 is 8279692279812.

21897229697280 is a `hidden beast` number, since 2 + 189 + 72 + 296 + 97 + 2 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 21897229697199 and 21897229697208.

It is not an unprimeable number, because it can be changed into a prime (21897229697281) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 7450570051 + ... + 7450572989.

It is an arithmetic number, because the mean of its divisors is an integer number (69391582260).

Almost surely, 2^{21897229697280} is an apocalyptic number.

21897229697280 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 21897229697280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44965745304480).

21897229697280 is an abundant number, since it is smaller than the sum of its proper divisors (68034260911680).

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

21897229697280 is a wasteful number, since it uses less digits than its factorization.

21897229697280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3244 (or 3220 counting only the distinct ones).

The product of its (nonzero) digits is 219469824, while the sum is 72.

The spelling of 21897229697280 in words is "twenty-one trillion, eight hundred ninety-seven billion, two hundred twenty-nine million, six hundred ninety-seven thousand, two hundred eighty".