221090842 has 12 divisors (see below), whose sum is σ = 385781130. Its totient is φ = 94753176.

The previous prime is 221090827. The next prime is 221090843. The reversal of 221090842 is 248090122.

It can be written as a sum of positive squares in only one way, i.e., 111281401 + 109809441 = 10549^2 + 10479^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221090842.

It is not an unprimeable number, because it can be changed into a prime (221090843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1127917 + ... + 1128112.

Almost surely, 2^221090842 is an apocalyptic number.

221090842 is a deficient number, since it is larger than the sum of its proper divisors (164690288).

221090842 is a wasteful number, since it uses less digits than its factorization.

221090842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2256045 (or 2256038 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 221090842 is about 14869.1237805057. The cubic root of 221090842 is about 604.6771877117.

The spelling of 221090842 in words is "two hundred twenty-one million, ninety thousand, eight hundred forty-two".