165221313 has 8 divisors (see below), whose sum is σ = 220516608. Its totient is φ = 110036784.

The previous prime is 165221293. The next prime is 165221333. The reversal of 165221313 is 313122561.

It is an interprime number because it is at equal distance from previous prime (165221293) and next prime (165221333).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165221313 - 2⁵ = 165221281 is a prime.

It is a super-3 number, since 3×165221313³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (165221333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24145 + ... + 30222.

It is an arithmetic number, because the mean of its divisors is an integer number (27564576).

Almost surely, 2^165221313 is an apocalyptic number.

It is an amenable number.

165221313 is a deficient number, since it is larger than the sum of its proper divisors (55295295).

165221313 is a wasteful number, since it uses less digits than its factorization.

165221313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55383.

The product of its digits is 1080, while the sum is 24.

The square root of 165221313 is about 12853.8442887721. The cubic root of 165221313 is about 548.7257697249.

Adding to 165221313 its reverse (313122561), we get a palindrome (478343874).

The spelling of 165221313 in words is "one hundred sixty-five million, two hundred twenty-one thousand, three hundred thirteen".