18420256 has 24 divisors (see below), whose sum is σ = 36952524. Its totient is φ = 9035520.

The previous prime is 18420251. The next prime is 18420271. The reversal of 18420256 is 65202481.

It can be written as a sum of positive squares in 2 ways, for example, as 18352656 + 67600 = 4284^2 + 260^2 .

It is a super-2 number, since 2×18420256² = 678611662211072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18420251) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3735 + ... + 7126.

Almost surely, 2^18420256 is an apocalyptic number.

18420256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18420256 is an abundant number, since it is smaller than the sum of its proper divisors (18532268).

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

18420256 is a wasteful number, since it uses less digits than its factorization.

18420256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10924 (or 10916 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 18420256 is about 4291.8825706210. The cubic root of 18420256 is about 264.0980658023.

The spelling of 18420256 in words is "eighteen million, four hundred twenty thousand, two hundred fifty-six".