18005020 has 48 divisors (see below), whose sum is σ = 41545728. Its totient is φ = 6500160.

The previous prime is 18004999. The next prime is 18005041. The reversal of 18005020 is 2050081.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18004999) and next prime (18005041).

It is a junction number, because it is equal to n+sod(n) for n = 18004985 and 18005003.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48877 + ... + 49243.

It is an arithmetic number, because the mean of its divisors is an integer number (865536).

Almost surely, 2^18005020 is an apocalyptic number.

18005020 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 18005020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20772864).

18005020 is an abundant number, since it is smaller than the sum of its proper divisors (23540708).

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

18005020 is a wasteful number, since it uses less digits than its factorization.

18005020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 18005020 is about 4243.2322585501. The cubic root of 18005020 is about 262.0985003449.

The spelling of 18005020 in words is "eighteen million, five thousand, twenty".