18859440 has 80 divisors (see below), whose sum is σ = 58924800. Its totient is φ = 4989696.

The previous prime is 18859417. The next prime is 18859441. The reversal of 18859440 is 4495881.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×18859440² = 711356954227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18859441) 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 15 ways as a sum of consecutive naturals, for example, 42741 + ... + 43179.

It is an arithmetic number, because the mean of its divisors is an integer number (736560).

Almost surely, 2^18859440 is an apocalyptic number.

18859440 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 18859440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29462400).

18859440 is an abundant number, since it is smaller than the sum of its proper divisors (40065360).

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

18859440 is a wasteful number, since it uses less digits than its factorization.

18859440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 634 (or 628 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 39.

The square root of 18859440 is about 4342.7456752612. The cubic root of 18859440 is about 266.1805170359.

It can be divided in two parts, 1885 and 9440, that added together give a triangular number (11325 = T₁₅₀).

The spelling of 18859440 in words is "eighteen million, eight hundred fifty-nine thousand, four hundred forty".