221981942 has 32 divisors (see below), whose sum is σ = 415027200. Its totient is φ = 86699808.

The previous prime is 221981939. The next prime is 221981957. The reversal of 221981942 is 249189122.

It is a junction number, because it is equal to n+sod(n) for n = 221981896 and 221981905.

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 15 ways as a sum of consecutive naturals, for example, 6659 + ... + 22097.

It is an arithmetic number, because the mean of its divisors is an integer number (12969600).

Almost surely, 2^221981942 is an apocalyptic number.

221981942 is a deficient number, since it is larger than the sum of its proper divisors (193045258).

221981942 is a wasteful number, since it uses less digits than its factorization.

221981942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15540.

The product of its digits is 20736, while the sum is 38.

The square root of 221981942 is about 14899.0584266255. The cubic root of 221981942 is about 605.4884764771.

The spelling of 221981942 in words is "two hundred twenty-one million, nine hundred eighty-one thousand, nine hundred forty-two".