164406521 has 2 divisors, whose sum is σ = 164406522. Its totient is φ = 164406520.

The previous prime is 164406511. The next prime is 164406523. The reversal of 164406521 is 125604461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94867600 + 69538921 = 9740^2 + 8339^2 .

It is an emirp because it is prime and its reverse (125604461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 164406521 - 2⁶ = 164406457 is a prime.

It is a super-3 number, since 3×164406521³ (a number of 26 digits) contains 333 as substring.

Together with 164406523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (164406523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82203260 + 82203261.

It is an arithmetic number, because the mean of its divisors is an integer number (82203261).

Almost surely, 2^164406521 is an apocalyptic number.

It is an amenable number.

164406521 is a deficient number, since it is larger than the sum of its proper divisors (1).

164406521 is an equidigital number, since it uses as much as digits as its factorization.

164406521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 164406521 is about 12822.1106296896. The cubic root of 164406521 is about 547.8222657402.

The spelling of 164406521 in words is "one hundred sixty-four million, four hundred six thousand, five hundred twenty-one".