21956882220 has 1008 divisors, whose sum is σ = 91400682240. Its totient is φ = 4323331584.

The previous prime is 21956882141. The next prime is 21956882243. The reversal of 21956882220 is 2228865912.

21956882220 is a `hidden beast` number, since 2 + 1 + 9 + 568 + 82 + 2 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 327714627 + ... + 327714693.

It is an arithmetic number, because the mean of its divisors is an integer number (90675280).

Almost surely, 2^21956882220 is an apocalyptic number.

21956882220 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 21956882220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45700341120).

21956882220 is an abundant number, since it is smaller than the sum of its proper divisors (69443800020).

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

21956882220 is a wasteful number, since it uses less digits than its factorization.

21956882220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 21956882220 in words is "twenty-one billion, nine hundred fifty-six million, eight hundred eighty-two thousand, two hundred twenty".