165632421 has 8 divisors (see below), whose sum is σ = 223953984. Its totient is φ = 108866240.

The previous prime is 165632399. The next prime is 165632429. The reversal of 165632421 is 124236561.

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

It is a cyclic number.

It is not a de Polignac number, because 165632421 - 2²⁵ = 132077989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165632429) 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 7 ways as a sum of consecutive naturals, for example, 388596 + ... + 389021.

It is an arithmetic number, because the mean of its divisors is an integer number (27994248).

Almost surely, 2^165632421 is an apocalyptic number.

It is an amenable number.

165632421 is a deficient number, since it is larger than the sum of its proper divisors (58321563).

165632421 is an equidigital number, since it uses as much as digits as its factorization.

165632421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777691.

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

The square root of 165632421 is about 12869.8259894996. The cubic root of 165632421 is about 549.1805107128.

Adding to 165632421 its reverse (124236561), we get a palindrome (289868982).

The spelling of 165632421 in words is "one hundred sixty-five million, six hundred thirty-two thousand, four hundred twenty-one".