1805209420 has 24 divisors (see below), whose sum is σ = 4332502944. Its totient is φ = 618928896.

The previous prime is 1805209411. The next prime is 1805209433. The reversal of 1805209420 is 249025081.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6447037 + ... + 6447316.

It is an arithmetic number, because the mean of its divisors is an integer number (180520956).

Almost surely, 2^1805209420 is an apocalyptic number.

1805209420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1805209420 is an abundant number, since it is smaller than the sum of its proper divisors (2527293524).

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

1805209420 is a wasteful number, since it uses less digits than its factorization.

1805209420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12894369 (or 12894367 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 1805209420 is about 42487.7561186749. The cubic root of 1805209420 is about 1217.6127779022.

The spelling of 1805209420 in words is "one billion, eight hundred five million, two hundred nine thousand, four hundred twenty".