164511521 has 2 divisors, whose sum is σ = 164511522. Its totient is φ = 164511520.

The previous prime is 164511517. The next prime is 164511553. The reversal of 164511521 is 125115461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164224225 + 287296 = 12815^2 + 536^2 .

It is a cyclic number.

It is not a de Polignac number, because 164511521 - 2² = 164511517 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (164511511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82255760 + 82255761.

It is an arithmetic number, because the mean of its divisors is an integer number (82255761).

Almost surely, 2^164511521 is an apocalyptic number.

It is an amenable number.

164511521 is a deficient number, since it is larger than the sum of its proper divisors (1).

164511521 is an equidigital number, since it uses as much as digits as its factorization.

164511521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 26.

The square root of 164511521 is about 12826.2044658582. The cubic root of 164511521 is about 547.9388651231.

Adding to 164511521 its reverse (125115461), we get a palindrome (289626982).

The spelling of 164511521 in words is "one hundred sixty-four million, five hundred eleven thousand, five hundred twenty-one".