21897952228980 has 96 divisors (see below), whose sum is σ = 69086497294080. Its totient is φ = 5757208087680.

The previous prime is 21897952228967. The next prime is 21897952228987. The reversal of 21897952228980 is 8982225979812.

21897952228980 is a `hidden beast` number, since 2 + 1 + 8 + 9 + 7 + 9 + 522 + 2 + 8 + 98 + 0 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21897952228899 and 21897952228908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21897952228987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 285537459 + ... + 285614138.

It is an arithmetic number, because the mean of its divisors is an integer number (719651013480).

Almost surely, 2^{21897952228980} is an apocalyptic number.

21897952228980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21897952228980 is an abundant number, since it is smaller than the sum of its proper divisors (47188545065100).

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

21897952228980 is a wasteful number, since it uses less digits than its factorization.

21897952228980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571151686 (or 571151678 counting only the distinct ones).

The product of its (nonzero) digits is 209018880, while the sum is 72.

The spelling of 21897952228980 in words is "twenty-one trillion, eight hundred ninety-seven billion, nine hundred fifty-two million, two hundred twenty-eight thousand, nine hundred eighty".