18505500 has 144 divisors (see below), whose sum is σ = 59151456. Its totient is φ = 4492800.

The previous prime is 18505493. The next prime is 18505507. The reversal of 18505500 is 550581.

It is an interprime number because it is at equal distance from previous prime (18505493) and next prime (18505507).

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18505507) 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 47 ways as a sum of consecutive naturals, for example, 253464 + ... + 253536.

It is an arithmetic number, because the mean of its divisors is an integer number (410774).

Almost surely, 2^18505500 is an apocalyptic number.

18505500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18505500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29575728).

18505500 is an abundant number, since it is smaller than the sum of its proper divisors (40645956).

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

18505500 is a wasteful number, since it uses less digits than its factorization.

18505500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 24.

The square root of 18505500 is about 4301.8019480213. The cubic root of 18505500 is about 264.5048306311.

The spelling of 18505500 in words is "eighteen million, five hundred five thousand, five hundred".