18051220 has 24 divisors (see below), whose sum is σ = 41354208. Its totient is φ = 6564000.

The previous prime is 18051211. The next prime is 18051223. The reversal of 18051220 is 2215081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18051223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40806 + ... + 41245.

It is an arithmetic number, because the mean of its divisors is an integer number (1723092).

Almost surely, 2^18051220 is an apocalyptic number.

18051220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18051220 is an abundant number, since it is smaller than the sum of its proper divisors (23302988).

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

18051220 is a wasteful number, since it uses less digits than its factorization.

18051220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82071 (or 82069 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 18051220 is about 4248.6727339253. The cubic root of 18051220 is about 262.3224861826.

It can be divided in two parts, 1805 and 1220, that added together give a square (3025 = 55²).

The spelling of 18051220 in words is "eighteen million, fifty-one thousand, two hundred twenty".