1818185840 has 40 divisors (see below), whose sum is σ = 4269155328. Its totient is φ = 720070400.

The previous prime is 1818185839. The next prime is 1818185843. The reversal of 1818185840 is 485818181.

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 = 1818185791 and 1818185800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818185843) 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, 104432 + ... + 120591.

Almost surely, 2^1818185840 is an apocalyptic number.

1818185840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1818185840 is an abundant number, since it is smaller than the sum of its proper divisors (2450969488).

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

1818185840 is a wasteful number, since it uses less digits than its factorization.

1818185840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225137 (or 225131 counting only the distinct ones).

The product of its (nonzero) digits is 81920, while the sum is 44.

The square root of 1818185840 is about 42640.1904310945. The cubic root of 1818185840 is about 1220.5233444015.

The spelling of 1818185840 in words is "one billion, eight hundred eighteen million, one hundred eighty-five thousand, eight hundred forty".