18987044 has 12 divisors (see below), whose sum is σ = 33257868. Its totient is φ = 9484800.

The previous prime is 18987041. The next prime is 18987047. The reversal of 18987044 is 44078981.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18987041) and next prime (18987047).

It can be written as a sum of positive squares in 2 ways, for example, as 9302500 + 9684544 = 3050^2 + 3112^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18986992 and 18987010.

It is not an unprimeable number, because it can be changed into a prime (18987041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7184 + ... + 9464.

It is an arithmetic number, because the mean of its divisors is an integer number (2771489).

Almost surely, 2^18987044 is an apocalyptic number.

It is an amenable number.

18987044 is a deficient number, since it is larger than the sum of its proper divisors (14270824).

18987044 is a wasteful number, since it uses less digits than its factorization.

18987044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4366 (or 4364 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 18987044 is about 4357.4125349799. The cubic root of 18987044 is about 266.7794987795.

The spelling of 18987044 in words is "eighteen million, nine hundred eighty-seven thousand, forty-four".