1808564840 has 16 divisors (see below), whose sum is σ = 4069270980. Its totient is φ = 723425920.

The previous prime is 1808564833. The next prime is 1808564867. The reversal of 1808564840 is 484658081.

It can be written as a sum of positive squares in 2 ways, for example, as 1799286724 + 9278116 = 42418^2 + 3046^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1808564791 and 1808564800.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22607021 + ... + 22607100.

Almost surely, 2^1808564840 is an apocalyptic number.

1808564840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1808564840 is an abundant number, since it is smaller than the sum of its proper divisors (2260706140).

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

1808564840 is a wasteful number, since it uses less digits than its factorization.

1808564840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45214132 (or 45214128 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 44.

The square root of 1808564840 is about 42527.2246919547. The cubic root of 1808564840 is about 1218.3667206251.

The spelling of 1808564840 in words is "one billion, eight hundred eight million, five hundred sixty-four thousand, eight hundred forty".