166433021 has 2 divisors, whose sum is σ = 166433022. Its totient is φ = 166433020.

The previous prime is 166432999. The next prime is 166433023. The reversal of 166433021 is 120334661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112572100 + 53860921 = 10610^2 + 7339^2 .

It is a cyclic number.

It is not a de Polignac number, because 166433021 - 2¹⁴ = 166416637 is a prime.

Together with 166433023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166433023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83216510 + 83216511.

It is an arithmetic number, because the mean of its divisors is an integer number (83216511).

Almost surely, 2^166433021 is an apocalyptic number.

It is an amenable number.

166433021 is a deficient number, since it is larger than the sum of its proper divisors (1).

166433021 is an equidigital number, since it uses as much as digits as its factorization.

166433021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 166433021 is about 12900.8922559643. The cubic root of 166433021 is about 550.0639275555.

Adding to 166433021 its reverse (120334661), we get a palindrome (286767682).

The spelling of 166433021 in words is "one hundred sixty-six million, four hundred thirty-three thousand, twenty-one".