1806865574809 has 9 divisors (see below), whose sum is σ = 1838090158293. Its totient is φ = 1776162771132.

The previous prime is 1806865574803. The next prime is 1806865574861. The reversal of 1806865574809 is 9084755686081.

The square root of 1806865574809 is 1344197.

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

It is not a de Polignac number, because 1806865574809 - 2²⁵ = 1806832020377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1806865574803) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 79296232 + ... + 79319014.

Almost surely, 2^{1806865574809} is an apocalyptic number.

1806865574809 is the 1344197-th square number.

1806865574809 is the 672099-th centered octagonal number.

It is an amenable number.

1806865574809 is a deficient number, since it is larger than the sum of its proper divisors (31224583484).

1806865574809 is an frugal number, since it uses more digits than its factorization.

1806865574809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45684 (or 22842 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 67.

The spelling of 1806865574809 in words is "one trillion, eight hundred six billion, eight hundred sixty-five million, five hundred seventy-four thousand, eight hundred nine".