1809896849 has 4 divisors (see below), whose sum is σ = 1809981936. Its totient is φ = 1809811764.

The previous prime is 1809896819. The next prime is 1809896861. The reversal of 1809896849 is 9486989081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1809896849 - 2²⁰ = 1808848273 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1809896791 and 1809896800.

It is not an unprimeable number, because it can be changed into a prime (1809896819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21122 + ... + 63764.

It is an arithmetic number, because the mean of its divisors is an integer number (452495484).

Almost surely, 2^1809896849 is an apocalyptic number.

It is an amenable number.

1809896849 is a deficient number, since it is larger than the sum of its proper divisors (85087).

1809896849 is an equidigital number, since it uses as much as digits as its factorization.

1809896849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85086.

The product of its (nonzero) digits is 8957952, while the sum is 62.

The square root of 1809896849 is about 42542.8824716897. The cubic root of 1809896849 is about 1218.6657564772.

The spelling of 1809896849 in words is "one billion, eight hundred nine million, eight hundred ninety-six thousand, eight hundred forty-nine".