1809213823 has 16 divisors (see below), whose sum is σ = 1869995392. Its totient is φ = 1749600000.

The previous prime is 1809213811. The next prime is 1809213829. The reversal of 1809213823 is 3283129081.

It is a cyclic number.

It is not a de Polignac number, because 1809213823 - 2²¹ = 1807116671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809213829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2408698 + ... + 2409448.

It is an arithmetic number, because the mean of its divisors is an integer number (116874712).

Almost surely, 2^1809213823 is an apocalyptic number.

1809213823 is a deficient number, since it is larger than the sum of its proper divisors (60781569).

1809213823 is an equidigital number, since it uses as much as digits as its factorization.

1809213823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1426.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 1809213823 is about 42534.8542139267. The cubic root of 1809213823 is about 1218.5124355613.

The spelling of 1809213823 in words is "one billion, eight hundred nine million, two hundred thirteen thousand, eight hundred twenty-three".