221221442 has 16 divisors (see below), whose sum is σ = 378379512. Its totient is φ = 96096000.

The previous prime is 221221423. The next prime is 221221447. The reversal of 221221442 is 244122122.

It can be written as a sum of positive squares in 4 ways, for example, as 194295721 + 26925721 = 13939^2 + 5189^2 .

It is not an unprimeable number, because it can be changed into a prime (221221447) 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 7 ways as a sum of consecutive naturals, for example, 249809 + ... + 250692.

Almost surely, 2^221221442 is an apocalyptic number.

221221442 is a deficient number, since it is larger than the sum of its proper divisors (157158070).

221221442 is a wasteful number, since it uses less digits than its factorization.

221221442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500533.

The product of its digits is 512, while the sum is 20.

The square root of 221221442 is about 14873.5147829960. The cubic root of 221221442 is about 604.7962267087.

Adding to 221221442 its reverse (244122122), we get a palindrome (465343564).

The spelling of 221221442 in words is "two hundred twenty-one million, two hundred twenty-one thousand, four hundred forty-two".