221986856 has 96 divisors (see below), whose sum is σ = 527063040. Its totient is φ = 87127488.

The previous prime is 221986819. The next prime is 221986871. The reversal of 221986856 is 658689122.

It is a self number, because there is not a number n which added to its sum of digits gives 221986856.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1747865 + ... + 1747991.

It is an arithmetic number, because the mean of its divisors is an integer number (5490240).

Almost surely, 2^221986856 is an apocalyptic number.

221986856 is a gapful number since it is divisible by the number (26) 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 221986856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263531520).

221986856 is an abundant number, since it is smaller than the sum of its proper divisors (305076184).

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

221986856 is an equidigital number, since it uses as much as digits as its factorization.

221986856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181 (or 149 counting only the distinct ones).

The product of its digits is 414720, while the sum is 47.

The square root of 221986856 is about 14899.2233354628. The cubic root of 221986856 is about 605.4929443307.

The spelling of 221986856 in words is "two hundred twenty-one million, nine hundred eighty-six thousand, eight hundred fifty-six".