221600161 has 8 divisors (see below), whose sum is σ = 225858600. Its totient is φ = 217382400.

The previous prime is 221600153. The next prime is 221600167. The reversal of 221600161 is 161006122.

221600161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 160275600 + 61324561 = 12660^2 + 7831^2 .

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 221600161 - 2³ = 221600153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221600167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 945 + ... + 21073.

It is an arithmetic number, because the mean of its divisors is an integer number (28232325).

Almost surely, 2^221600161 is an apocalyptic number.

It is an amenable number.

221600161 is a deficient number, since it is larger than the sum of its proper divisors (4258439).

221600161 is a wasteful number, since it uses less digits than its factorization.

221600161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20339.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 221600161 is about 14886.2406604220. The cubic root of 221600161 is about 605.1411559623.

Adding to 221600161 its reverse (161006122), we get a palindrome (382606283).

The spelling of 221600161 in words is "two hundred twenty-one million, six hundred thousand, one hundred sixty-one".