165410221 has 4 divisors (see below), whose sum is σ = 175140252. Its totient is φ = 155680192.

The previous prime is 165410213. The next prime is 165410237. The reversal of 165410221 is 122014561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 128029225 + 37380996 = 11315^2 + 6114^2 .

It is a cyclic number.

It is not a de Polignac number, because 165410221 - 2³ = 165410213 is a prime.

It is a super-2 number, since 2×165410221² = 54721082422537682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165410192 and 165410201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165410251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4864990 + ... + 4865023.

It is an arithmetic number, because the mean of its divisors is an integer number (43785063).

Almost surely, 2^165410221 is an apocalyptic number.

It is an amenable number.

165410221 is a deficient number, since it is larger than the sum of its proper divisors (9730031).

165410221 is an equidigital number, since it uses as much as digits as its factorization.

165410221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9730030.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 165410221 is about 12861.1904969952. The cubic root of 165410221 is about 548.9348210560.

Adding to 165410221 its reverse (122014561), we get a palindrome (287424782).

The spelling of 165410221 in words is "one hundred sixty-five million, four hundred ten thousand, two hundred twenty-one".