18780444 has 96 divisors (see below), whose sum is σ = 52799040. Its totient is φ = 5750784.

The previous prime is 18780431. The next prime is 18780473. The reversal of 18780444 is 44408781.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 18780399 and 18780408.

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 31 ways as a sum of consecutive naturals, for example, 97212 + ... + 97404.

It is an arithmetic number, because the mean of its divisors is an integer number (549990).

Almost surely, 2^18780444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18780444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26399520).

18780444 is an abundant number, since it is smaller than the sum of its proper divisors (34018596).

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

18780444 is a wasteful number, since it uses less digits than its factorization.

18780444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The square root of 18780444 is about 4333.6409634394. The cubic root of 18780444 is about 265.8083493344.

The spelling of 18780444 in words is "eighteen million, seven hundred eighty thousand, four hundred forty-four".