221986644 has 24 divisors (see below), whose sum is σ = 565057248. Its totient is φ = 67268640.

The previous prime is 221986553. The next prime is 221986679. The reversal of 221986644 is 446689122.

It is a super-2 number, since 2×221986644² = 98556140228765472, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221986596 and 221986605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 840727 + ... + 840990.

It is an arithmetic number, because the mean of its divisors is an integer number (23544052).

Almost surely, 2^221986644 is an apocalyptic number.

It is an amenable number.

221986644 is an abundant number, since it is smaller than the sum of its proper divisors (343070604).

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

221986644 is a wasteful number, since it uses less digits than its factorization.

221986644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1681735 (or 1681733 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The square root of 221986644 is about 14899.2162209963. The cubic root of 221986644 is about 605.4927515797.

The spelling of 221986644 in words is "two hundred twenty-one million, nine hundred eighty-six thousand, six hundred forty-four".