165420 has 36 divisors (see below), whose sum is σ = 502320. Its totient is φ = 44064.

The previous prime is 165397. The next prime is 165437. The reversal of 165420 is 24561.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 165393 and 165402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 280 + ... + 639.

2¹⁶⁵⁴²⁰ is an apocalyptic number.

165420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165420 is an abundant number, since it is smaller than the sum of its proper divisors (336900).

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

165420 is a wasteful number, since it uses less digits than its factorization.

165420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934 (or 929 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 165420 is about 406.7185759220. The cubic root of 165420 is about 54.8945638461.

Adding to 165420 its reverse (24561), we get a palindrome (189981).

It can be divided in two parts, 165 and 420, that added together give a palindrome (585).

The spelling of 165420 in words is "one hundred sixty-five thousand, four hundred twenty".