165468621 has 4 divisors (see below), whose sum is σ = 220624832. Its totient is φ = 110312412.

The previous prime is 165468617. The next prime is 165468631. The reversal of 165468621 is 126864561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 165468621 - 2² = 165468617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165468621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165468631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27578101 + ... + 27578106.

It is an arithmetic number, because the mean of its divisors is an integer number (55156208).

Almost surely, 2^165468621 is an apocalyptic number.

It is an amenable number.

165468621 is a deficient number, since it is larger than the sum of its proper divisors (55156211).

165468621 is an equidigital number, since it uses as much as digits as its factorization.

165468621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55156210.

The product of its digits is 69120, while the sum is 39.

The square root of 165468621 is about 12863.4606929862. The cubic root of 165468621 is about 548.9994160597. Note that the first 3 decimals are identical.

The spelling of 165468621 in words is "one hundred sixty-five million, four hundred sixty-eight thousand, six hundred twenty-one".