18840040 has 32 divisors (see below), whose sum is σ = 42525000. Its totient is φ = 7512064.

The previous prime is 18840037. The next prime is 18840043. The reversal of 18840040 is 4004881.

It is an interprime number because it is at equal distance from previous prime (18840037) and next prime (18840043).

It can be written as a sum of positive squares in 4 ways, for example, as 18301284 + 538756 = 4278^2 + 734^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18839987 and 18840014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18840043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17436 + ... + 18484.

Almost surely, 2^18840040 is an apocalyptic number.

18840040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18840040 is an abundant number, since it is smaller than the sum of its proper divisors (23684960).

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

18840040 is a wasteful number, since it uses less digits than its factorization.

18840040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1509 (or 1505 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 18840040 is about 4340.5114905965. The cubic root of 18840040 is about 266.0892157445.

The spelling of 18840040 in words is "eighteen million, eight hundred forty thousand, forty".