164240221 has 4 divisors (see below), whose sum is σ = 164344032. Its totient is φ = 164136412.

The previous prime is 164240203. The next prime is 164240233. The reversal of 164240221 is 122042461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 164240221 - 2⁹ = 164239709 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 164240192 and 164240201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164240261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49495 + ... + 52708.

It is an arithmetic number, because the mean of its divisors is an integer number (41086008).

Almost surely, 2^164240221 is an apocalyptic number.

It is an amenable number.

164240221 is a deficient number, since it is larger than the sum of its proper divisors (103811).

164240221 is a wasteful number, since it uses less digits than its factorization.

164240221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103810.

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

The square root of 164240221 is about 12815.6240971714. The cubic root of 164240221 is about 547.6374929042.

Adding to 164240221 its reverse (122042461), we get a palindrome (286282682).

It can be divided in two parts, 164240 and 221, that added together give a palindrome (164461).

The spelling of 164240221 in words is "one hundred sixty-four million, two hundred forty thousand, two hundred twenty-one".