18039780 has 96 divisors (see below), whose sum is σ = 61246080. Its totient is φ = 4371840.

The previous prime is 18039779. The next prime is 18039803. The reversal of 18039780 is 8793081.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 31 ways as a sum of consecutive naturals, for example, 4422 + ... + 7458.

It is an arithmetic number, because the mean of its divisors is an integer number (637980).

Almost surely, 2^18039780 is an apocalyptic number.

18039780 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 18039780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30623040).

18039780 is an abundant number, since it is smaller than the sum of its proper divisors (43206300).

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

18039780 is a wasteful number, since it uses less digits than its factorization.

18039780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3066 (or 3058 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 18039780 is about 4247.3262177516. The cubic root of 18039780 is about 262.2670586561.

18039780 divided by its sum of digits (36) gives a palindrome (501105).

The spelling of 18039780 in words is "eighteen million, thirty-nine thousand, seven hundred eighty".