420090 has 64 divisors (see below), whose sum is σ = 1175040. Its totient is φ = 95040.

The previous prime is 420073. The next prime is 420097. The reversal of 420090 is 90024.

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

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 420090.

It is not an unprimeable number, because it can be changed into a prime (420097) by changing a digit.

420090 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 (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6237 + ... + 6303.

It is an arithmetic number, because the mean of its divisors is an integer number (18360).

2⁴²⁰⁰⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 420090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (587520).

420090 is an abundant number, since it is smaller than the sum of its proper divisors (754950).

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

420090 is a wasteful number, since it uses less digits than its factorization.

420090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107.

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

The square root of 420090 is about 648.1435026289. The cubic root of 420090 is about 74.8940726847.

The spelling of 420090 in words is "four hundred twenty thousand, ninety".