166233521 has 2 divisors, whose sum is σ = 166233522. Its totient is φ = 166233520.

The previous prime is 166233491. The next prime is 166233523. The reversal of 166233521 is 125332661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100801600 + 65431921 = 10040^2 + 8089^2 .

It is an emirp because it is prime and its reverse (125332661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166233521 - 2¹⁴ = 166217137 is a prime.

Together with 166233523, 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 (166233523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83116760 + 83116761.

It is an arithmetic number, because the mean of its divisors is an integer number (83116761).

Almost surely, 2^166233521 is an apocalyptic number.

It is an amenable number.

166233521 is a deficient number, since it is larger than the sum of its proper divisors (1).

166233521 is an equidigital number, since it uses as much as digits as its factorization.

166233521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 29.

The square root of 166233521 is about 12893.1579141807. The cubic root of 166233521 is about 549.8440560642.

The spelling of 166233521 in words is "one hundred sixty-six million, two hundred thirty-three thousand, five hundred twenty-one".