165233221 has 2 divisors, whose sum is σ = 165233222. Its totient is φ = 165233220.

The previous prime is 165233203. The next prime is 165233227. The reversal of 165233221 is 122332561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155900196 + 9333025 = 12486^2 + 3055^2 .

It is a cyclic number.

It is not a de Polignac number, because 165233221 - 2⁷ = 165233093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165233227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82616610 + 82616611.

It is an arithmetic number, because the mean of its divisors is an integer number (82616611).

Almost surely, 2^165233221 is an apocalyptic number.

It is an amenable number.

165233221 is a deficient number, since it is larger than the sum of its proper divisors (1).

165233221 is an equidigital number, since it uses as much as digits as its factorization.

165233221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 25.

The square root of 165233221 is about 12854.3074881535. The cubic root of 165233221 is about 548.7389521837.

Adding to 165233221 its reverse (122332561), we get a palindrome (287565782).

The spelling of 165233221 in words is "one hundred sixty-five million, two hundred thirty-three thousand, two hundred twenty-one".