164820217 has 4 divisors (see below), whose sum is σ = 167613840. Its totient is φ = 162026596.

The previous prime is 164820191. The next prime is 164820233. The reversal of 164820217 is 712028461.

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, and also an emirpimes, since its reverse is a distinct semiprime: 712028461 = 59 ⋅12068279.

It is a cyclic number.

It is not a de Polignac number, because 164820217 - 2¹⁵ = 164787449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164820017) 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 3 ways as a sum of consecutive naturals, for example, 1396723 + ... + 1396840.

It is an arithmetic number, because the mean of its divisors is an integer number (41903460).

Almost surely, 2^164820217 is an apocalyptic number.

It is an amenable number.

164820217 is a deficient number, since it is larger than the sum of its proper divisors (2793623).

164820217 is an equidigital number, since it uses as much as digits as its factorization.

164820217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2793622.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 164820217 is about 12838.2326275855. The cubic root of 164820217 is about 548.2813757819.

Adding to 164820217 its reverse (712028461), we get a palindrome (876848678).

The spelling of 164820217 in words is "one hundred sixty-four million, eight hundred twenty thousand, two hundred seventeen".