164521 has 8 divisors (see below), whose sum is σ = 198080. Its totient is φ = 133488.

The previous prime is 164513. The next prime is 164531. The reversal of 164521 is 125461.

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 164521 - 2³ = 164513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 486 + ... + 751.

It is an arithmetic number, because the mean of its divisors is an integer number (24760).

2¹⁶⁴⁵²¹ is an apocalyptic number.

It is an amenable number.

164521 is a deficient number, since it is larger than the sum of its proper divisors (33559).

164521 is a wasteful number, since it uses less digits than its factorization.

164521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1263.

The product of its digits is 240, while the sum is 19.

The square root of 164521 is about 405.6118834551. The cubic root of 164521 is about 54.7949388829.

Adding to 164521 its reverse (125461), we get a palindrome (289982).

Subtracting from 164521 its reverse (125461), we obtain a triangular number (39060 = T₂₇₉).

The spelling of 164521 in words is "one hundred sixty-four thousand, five hundred twenty-one".