164321521 has 16 divisors (see below), whose sum is σ = 203616000. Its totient is φ = 129129408.

The previous prime is 164321513. The next prime is 164321543. The reversal of 164321521 is 125123461.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 164321521 - 2³ = 164321513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (164327521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7500 + ... + 19618.

It is an arithmetic number, because the mean of its divisors is an integer number (12726000).

Almost surely, 2^164321521 is an apocalyptic number.

It is an amenable number.

164321521 is a deficient number, since it is larger than the sum of its proper divisors (39294479).

164321521 is a wasteful number, since it uses less digits than its factorization.

164321521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12288.

The product of its digits is 1440, while the sum is 25.

The square root of 164321521 is about 12818.7956142533. The cubic root of 164321521 is about 547.7278393970.

Adding to 164321521 its reverse (125123461), we get a palindrome (289444982).

The spelling of 164321521 in words is "one hundred sixty-four million, three hundred twenty-one thousand, five hundred twenty-one".