221200161 has 24 divisors (see below), whose sum is σ = 369480384. Its totient is φ = 116676000.

The previous prime is 221200151. The next prime is 221200169. The reversal of 221200161 is 161002122.

It is not a de Polignac number, because 221200161 - 2¹⁰ = 221199137 is a prime.

It is a super-2 number, since 2×221200161² = 97859022452851842, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 221200161.

It is not an unprimeable number, because it can be changed into a prime (221200169) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 55965 + ... + 59786.

It is an arithmetic number, because the mean of its divisors is an integer number (15395016).

Almost surely, 2^221200161 is an apocalyptic number.

221200161 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221200161 is a deficient number, since it is larger than the sum of its proper divisors (148280223).

221200161 is a wasteful number, since it uses less digits than its factorization.

221200161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115781 (or 115774 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 221200161 is about 14872.7993666290. The cubic root of 221200161 is about 604.7768327460.

Adding to 221200161 its reverse (161002122), we get a palindrome (382202283).

The spelling of 221200161 in words is "two hundred twenty-one million, two hundred thousand, one hundred sixty-one".