221221642 has 8 divisors (see below), whose sum is σ = 342536832. Its totient is φ = 107042700.

The previous prime is 221221633. The next prime is 221221667. The reversal of 221221642 is 246122122.

221221642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1783984 + ... + 1784107.

It is an arithmetic number, because the mean of its divisors is an integer number (42817104).

Almost surely, 2^221221642 is an apocalyptic number.

221221642 is a deficient number, since it is larger than the sum of its proper divisors (121315190).

221221642 is a wasteful number, since it uses less digits than its factorization.

221221642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3568124.

The product of its digits is 768, while the sum is 22.

The square root of 221221642 is about 14873.5215063548. The cubic root of 221221642 is about 604.7964089684.

Adding to 221221642 its reverse (246122122), we get a palindrome (467343764).

The spelling of 221221642 in words is "two hundred twenty-one million, two hundred twenty-one thousand, six hundred forty-two".