18218530 has 64 divisors (see below), whose sum is σ = 39398400. Its totient is φ = 5987520.

The previous prime is 18218527. The next prime is 18218561. The reversal of 18218530 is 3581281.

18218530 = 1² + 2² + ... + 379².

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47881 + ... + 48259.

It is an arithmetic number, because the mean of its divisors is an integer number (615600).

Almost surely, 2^18218530 is an apocalyptic number.

18218530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18218530 is an abundant number, since it is smaller than the sum of its proper divisors (21179870).

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

18218530 is a wasteful number, since it uses less digits than its factorization.

18218530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 18218530 is about 4268.3169985370. The cubic root of 18218530 is about 263.1304513627.

The spelling of 18218530 in words is "eighteen million, two hundred eighteen thousand, five hundred thirty".