18018550 has 36 divisors (see below), whose sum is σ = 36764388. Its totient is φ = 6516000.

The previous prime is 18018529. The next prime is 18018551. The reversal of 18018550 is 5581081.

18018550 = 374² + 375² + ... + 473².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18018551) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 99460 + ... + 99640.

It is an arithmetic number, because the mean of its divisors is an integer number (1021233).

Almost surely, 2^18018550 is an apocalyptic number.

18018550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18018550 is an abundant number, since it is smaller than the sum of its proper divisors (18745838).

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

18018550 is a wasteful number, since it uses less digits than its factorization.

18018550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 28.

The square root of 18018550 is about 4244.8262626402. The cubic root of 18018550 is about 262.1641358326.

The spelling of 18018550 in words is "eighteen million, eighteen thousand, five hundred fifty".