166232021 has 2 divisors, whose sum is σ = 166232022. Its totient is φ = 166232020.

The previous prime is 166231993. The next prime is 166232039. The reversal of 166232021 is 120232661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148474225 + 17757796 = 12185^2 + 4214^2 .

It is a cyclic number.

It is not a de Polignac number, because 166232021 - 2⁶ = 166231957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166235021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83116010 + 83116011.

It is an arithmetic number, because the mean of its divisors is an integer number (83116011).

Almost surely, 2^166232021 is an apocalyptic number.

It is an amenable number.

166232021 is a deficient number, since it is larger than the sum of its proper divisors (1).

166232021 is an equidigital number, since it uses as much as digits as its factorization.

166232021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 166232021 is about 12893.0997436613. The cubic root of 166232021 is about 549.8424022289.

Adding to 166232021 its reverse (120232661), we get a palindrome (286464682).

The spelling of 166232021 in words is "one hundred sixty-six million, two hundred thirty-two thousand, twenty-one".