221601242 has 4 divisors (see below), whose sum is σ = 332401866. Its totient is φ = 110800620.

The previous prime is 221601229. The next prime is 221601257. The reversal of 221601242 is 242106122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242106122 = 2 ⋅121053061.

It can be written as a sum of positive squares in only one way, i.e., 218182441 + 3418801 = 14771^2 + 1849^2 .

It is a super-2 number, since 2×221601242² = 98214220911885128, which contains 22 as substring.

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 as a sum of consecutive naturals, namely, 55400309 + ... + 55400312.

Almost surely, 2^221601242 is an apocalyptic number.

221601242 is a deficient number, since it is larger than the sum of its proper divisors (110800624).

221601242 is a wasteful number, since it uses less digits than its factorization.

221601242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110800623.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 221601242 is about 14886.2769690746. The cubic root of 221601242 is about 605.1421399515.

Adding to 221601242 its reverse (242106122), we get a palindrome (463707364).

The spelling of 221601242 in words is "two hundred twenty-one million, six hundred one thousand, two hundred forty-two".