165421644 has 24 divisors (see below), whose sum is σ = 386642928. Its totient is φ = 55046400.

The previous prime is 165421621. The next prime is 165421687. The reversal of 165421644 is 446124561.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4257 + ... + 18680.

It is an arithmetic number, because the mean of its divisors is an integer number (16110122).

Almost surely, 2^165421644 is an apocalyptic number.

It is an amenable number.

165421644 is an abundant number, since it is smaller than the sum of its proper divisors (221221284).

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

165421644 is a wasteful number, since it uses less digits than its factorization.

165421644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23545 (or 23543 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 165421644 is about 12861.6345773000. The cubic root of 165421644 is about 548.9474569905.

The spelling of 165421644 in words is "one hundred sixty-five million, four hundred twenty-one thousand, six hundred forty-four".