18735440 has 20 divisors (see below), whose sum is σ = 43560084. Its totient is φ = 7494144.

The previous prime is 18735433. The next prime is 18735443. The reversal of 18735440 is 4453781.

It can be written as a sum of positive squares in 2 ways, for example, as 8133904 + 10601536 = 2852^2 + 3256^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 18735397 and 18735406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18735443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117017 + ... + 117176.

Almost surely, 2^18735440 is an apocalyptic number.

18735440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18735440 is an abundant number, since it is smaller than the sum of its proper divisors (24824644).

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

18735440 is a wasteful number, since it uses less digits than its factorization.

18735440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234206 (or 234200 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 18735440 is about 4328.4454484260. The cubic root of 18735440 is about 265.5958586716.

The spelling of 18735440 in words is "eighteen million, seven hundred thirty-five thousand, four hundred forty".