18781842 has 32 divisors (see below), whose sum is σ = 40147200. Its totient is φ = 5840208.

The previous prime is 18781831. The next prime is 18781891. The reversal of 18781842 is 24818781.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 18781842.

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, 6409 + ... + 8867.

It is an arithmetic number, because the mean of its divisors is an integer number (1254600).

Almost surely, 2^18781842 is an apocalyptic number.

18781842 is an abundant number, since it is smaller than the sum of its proper divisors (21365358).

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

18781842 is a wasteful number, since it uses less digits than its factorization.

18781842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2550.

The product of its digits is 28672, while the sum is 39.

The square root of 18781842 is about 4333.8022566795. The cubic root of 18781842 is about 265.8149446853.

The spelling of 18781842 in words is "eighteen million, seven hundred eighty-one thousand, eight hundred forty-two".