1808545729 has 15 divisors (see below), whose sum is σ = 1935611153. Its totient is φ = 1689682764.

The previous prime is 1808545721. The next prime is 1808545757. The reversal of 1808545729 is 9275458081.

It is a happy number.

The square root of 1808545729 is 42527.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1808545729 - 2³ = 1808545721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1808545721) by changing a digit.

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 14 ways as a sum of consecutive naturals, for example, 42059182 + ... + 42059224.

Almost surely, 2^1808545729 is an apocalyptic number.

1808545729 is the 42527-th square number.

1808545729 is the 21264-th centered octagonal number.

It is an amenable number.

1808545729 is a deficient number, since it is larger than the sum of its proper divisors (127065424).

1808545729 is an frugal number, since it uses more digits than its factorization.

1808545729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 49.

The cubic root of 1808545729 is about 1218.3624291398.

Multiplying 1808545729 by its sum of digits (49), we get a square (88618740721 = 297689²).

The spelling of 1808545729 in words is "one billion, eight hundred eight million, five hundred forty-five thousand, seven hundred twenty-nine".