18420210 has 40 divisors (see below), whose sum is σ = 49532076. Its totient is φ = 4911840.

The previous prime is 18420209. The next prime is 18420221. The reversal of 18420210 is 1202481.

It can be written as a sum of positive squares in 2 ways, for example, as 16621929 + 1798281 = 4077^2 + 1341^2 .

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

It is an unprimeable 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 19 ways as a sum of consecutive naturals, for example, 10561 + ... + 12180.

Almost surely, 2^18420210 is an apocalyptic number.

18420210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18420210 is an abundant number, since it is smaller than the sum of its proper divisors (31111866).

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

18420210 is a wasteful number, since it uses less digits than its factorization.

18420210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22760 (or 22751 counting only the distinct ones).

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

The square root of 18420210 is about 4291.8772116639. The cubic root of 18420210 is about 264.0978459624.

Adding to 18420210 its reverse (1202481), we get a palindrome (19622691).

The spelling of 18420210 in words is "eighteen million, four hundred twenty thousand, two hundred ten".