221642 has 4 divisors (see below), whose sum is σ = 332466. Its totient is φ = 110820.

The previous prime is 221623. The next prime is 221653. The reversal of 221642 is 246122.

221642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 219961 + 1681 = 469^2 + 41^2 .

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 221642.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55409 + ... + 55412.

2²²¹⁶⁴² is an apocalyptic number.

221642 is a deficient number, since it is larger than the sum of its proper divisors (110824).

221642 is a wasteful number, since it uses less digits than its factorization.

221642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110823.

The product of its digits is 192, while the sum is 17.

The square root of 221642 is about 470.7886999494. The cubic root of 221642 is about 60.5179237926.

Adding to 221642 its reverse (246122), we get a palindrome (467764).

The spelling of 221642 in words is "two hundred twenty-one thousand, six hundred forty-two".