1808908240 has 20 divisors (see below), whose sum is σ = 4205711844. Its totient is φ = 723563264.

The previous prime is 1808908237. The next prime is 1808908253. The reversal of 1808908240 is 428098081.

It can be written as a sum of positive squares in 2 ways, for example, as 815902096 + 993006144 = 28564^2 + 31512^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1808908193 and 1808908202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11305597 + ... + 11305756.

Almost surely, 2^1808908240 is an apocalyptic number.

1808908240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1808908240 is an abundant number, since it is smaller than the sum of its proper divisors (2396803604).

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

1808908240 is a wasteful number, since it uses less digits than its factorization.

1808908240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22611366 (or 22611360 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 40.

The square root of 1808908240 is about 42531.2619140321. The cubic root of 1808908240 is about 1218.4438279250.

The spelling of 1808908240 in words is "one billion, eight hundred eight million, nine hundred eight thousand, two hundred forty".