18987845 has 16 divisors (see below), whose sum is σ = 23565168. Its totient is φ = 14676480.

The previous prime is 18987803. The next prime is 18987853. The reversal of 18987845 is 54878981.

It can be written as a sum of positive squares in 8 ways, for example, as 2455489 + 16532356 = 1567^2 + 4066^2 .

It is not a de Polignac number, because 18987845 - 2¹⁴ = 18971461 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18987793 and 18987802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36185 + ... + 36705.

It is an arithmetic number, because the mean of its divisors is an integer number (1472823).

Almost surely, 2^18987845 is an apocalyptic number.

It is an amenable number.

18987845 is a deficient number, since it is larger than the sum of its proper divisors (4577323).

18987845 is a wasteful number, since it uses less digits than its factorization.

18987845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760.

The product of its digits is 645120, while the sum is 50.

The square root of 18987845 is about 4357.5044463546. The cubic root of 18987845 is about 266.7832502389.

The spelling of 18987845 in words is "eighteen million, nine hundred eighty-seven thousand, eight hundred forty-five".