18210420 has 84 divisors (see below), whose sum is σ = 57382500. Its totient is φ = 4852224.

The previous prime is 18210419. The next prime is 18210427. The reversal of 18210420 is 2401281.

It can be written as a sum of positive squares in 2 ways, for example, as 7001316 + 11209104 = 2646^2 + 3348^2 .

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 = 18210393 and 18210402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18210427) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 13956 + ... + 15204.

It is an arithmetic number, because the mean of its divisors is an integer number (683125).

Almost surely, 2^18210420 is an apocalyptic number.

18210420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18210420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28691250).

18210420 is an abundant number, since it is smaller than the sum of its proper divisors (39172080).

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

18210420 is a wasteful number, since it uses less digits than its factorization.

18210420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276 (or 1259 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 18210420 is about 4267.3668696282. The cubic root of 18210420 is about 263.0914012914.

The spelling of 18210420 in words is "eighteen million, two hundred ten thousand, four hundred twenty".