18449840 has 40 divisors (see below), whose sum is σ = 43138608. Its totient is φ = 7338240.

The previous prime is 18449839. The next prime is 18449861. The reversal of 18449840 is 4894481.

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 = 18449794 and 18449803.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16334 + ... + 17426.

Almost surely, 2^18449840 is an apocalyptic number.

18449840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18449840 is an abundant number, since it is smaller than the sum of its proper divisors (24688768).

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

18449840 is a wasteful number, since it uses less digits than its factorization.

18449840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1317 (or 1311 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 38.

The square root of 18449840 is about 4295.3276941346. The cubic root of 18449840 is about 264.2393757847.

The spelling of 18449840 in words is "eighteen million, four hundred forty-nine thousand, eight hundred forty".