90420 has 48 divisors (see below), whose sum is σ = 278208. Its totient is φ = 21760.

The previous prime is 90407. The next prime is 90437. The reversal of 90420 is 2409.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 90420.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 90420.

It is an unprimeable number.

90420 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 15 ways as a sum of consecutive naturals, for example, 592 + ... + 728.

It is an arithmetic number, because the mean of its divisors is an integer number (5796).

2⁹⁰⁴²⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139104).

90420 is an abundant number, since it is smaller than the sum of its proper divisors (187788).

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

90420 is a wasteful number, since it uses less digits than its factorization.

90420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 90420 is about 300.6991852333. The cubic root of 90420 is about 44.8836500474.

Adding to 90420 its reverse (2409), we get a palindrome (92829).

The spelling of 90420 in words is "ninety thousand, four hundred twenty".