18807440 has 40 divisors (see below), whose sum is σ = 46302840. Its totient is φ = 7079936.

The previous prime is 18807413. The next prime is 18807443. The reversal of 18807440 is 4470881.

It can be written as a sum of positive squares in 4 ways, for example, as 1401856 + 17405584 = 1184^2 + 4172^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 18807397 and 18807406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18807443) 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 7 ways as a sum of consecutive naturals, for example, 5555 + ... + 8274.

It is an arithmetic number, because the mean of its divisors is an integer number (1157571).

Almost surely, 2^18807440 is an apocalyptic number.

18807440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18807440 is an abundant number, since it is smaller than the sum of its proper divisors (27495400).

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

18807440 is a wasteful number, since it uses less digits than its factorization.

18807440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13859 (or 13853 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 18807440 is about 4336.7545468933. The cubic root of 18807440 is about 265.9356506675.

The spelling of 18807440 in words is "eighteen million, eight hundred seven thousand, four hundred forty".