165221436 has 24 divisors (see below), whose sum is σ = 408194640. Its totient is φ = 51834112.

The previous prime is 165221429. The next prime is 165221449. The reversal of 165221436 is 634122561.

It is a congruent number.

It is an unprimeable number.

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, 404751 + ... + 405158.

It is an arithmetic number, because the mean of its divisors is an integer number (17008110).

Almost surely, 2^165221436 is an apocalyptic number.

It is an amenable number.

165221436 is an abundant number, since it is smaller than the sum of its proper divisors (242973204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165221436 is a wasteful number, since it uses less digits than its factorization.

165221436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809933 (or 809931 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 165221436 is about 12853.8490733321. The cubic root of 165221436 is about 548.7259058922.

Adding to 165221436 its reverse (634122561), we get a palindrome (799343997).

The spelling of 165221436 in words is "one hundred sixty-five million, two hundred twenty-one thousand, four hundred thirty-six".