221601611 has 8 divisors (see below), whose sum is σ = 276282624. Its totient is φ = 172676520.

The previous prime is 221601599. The next prime is 221601631. The reversal of 221601611 is 116106122.

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

It is a cyclic number.

It is not a de Polignac number, because 221601611 - 2¹⁸ = 221339467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221601631) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 1438895 + ... + 1439048.

It is an arithmetic number, because the mean of its divisors is an integer number (34535328).

Almost surely, 2^221601611 is an apocalyptic number.

221601611 is a deficient number, since it is larger than the sum of its proper divisors (54681013).

221601611 is a wasteful number, since it uses less digits than its factorization.

221601611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2877961.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 221601611 is about 14886.2893630347. The cubic root of 221601611 is about 605.1424758361.

Adding to 221601611 its reverse (116106122), we get a palindrome (337707733).

The spelling of 221601611 in words is "two hundred twenty-one million, six hundred one thousand, six hundred eleven".