18128550 has 48 divisors (see below), whose sum is σ = 49050432. Its totient is φ = 4394400.

The previous prime is 18128549. The next prime is 18128563. The reversal of 18128550 is 5582181.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3844 + ... + 7143.

It is an arithmetic number, because the mean of its divisors is an integer number (1021884).

Almost surely, 2^18128550 is an apocalyptic number.

18128550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18128550 is an abundant number, since it is smaller than the sum of its proper divisors (30921882).

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

18128550 is a wasteful number, since it uses less digits than its factorization.

18128550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11013 (or 11008 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 30.

The square root of 18128550 is about 4257.7634974244. The cubic root of 18128550 is about 262.6965421483.

The spelling of 18128550 in words is "eighteen million, one hundred twenty-eight thousand, five hundred fifty".