166268021 has 2 divisors, whose sum is σ = 166268022. Its totient is φ = 166268020.

The previous prime is 166268009. The next prime is 166268027. The reversal of 166268021 is 120862661.

166268021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151167025 + 15100996 = 12295^2 + 3886^2 .

It is a cyclic number.

It is not a de Polignac number, because 166268021 - 2¹⁸ = 166005877 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166268027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83134010 + 83134011.

It is an arithmetic number, because the mean of its divisors is an integer number (83134011).

Almost surely, 2^166268021 is an apocalyptic number.

It is an amenable number.

166268021 is a deficient number, since it is larger than the sum of its proper divisors (1).

166268021 is an equidigital number, since it uses as much as digits as its factorization.

166268021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 166268021 is about 12894.4957636970. The cubic root of 166268021 is about 549.8820915291.

The spelling of 166268021 in words is "one hundred sixty-six million, two hundred sixty-eight thousand, twenty-one".