811725855584809 has 27 divisors (see below), whose sum is σ = 900232562695557. Its totient is φ = 731370309331200.

The previous prime is 811725855584803. The next prime is 811725855584849. The reversal of 811725855584809 is 908485558527118.

The square root of 811725855584809 is 28490803.

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

It can be written as a sum of positive squares in 4 ways, for example, as 322410574082025 + 489315281502784 = 17955795^2 + 22120472^2 .

It is not a de Polignac number, because 811725855584809 - 2³³ = 811717265650217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811725855584803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 35414056669 + ... + 35414079589.

Almost surely, 2^{811725855584809} is an apocalyptic number.

811725855584809 is the 28490803-rd square number.

811725855584809 is the 14245402-nd centered octagonal number.

It is an amenable number.

811725855584809 is a deficient number, since it is larger than the sum of its proper divisors (88506707110748).

811725855584809 is an frugal number, since it uses more digits than its factorization.

811725855584809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46090 (or 23045 counting only the distinct ones).

The product of its (nonzero) digits is 1290240000, while the sum is 76.

The spelling of 811725855584809 in words is "eight hundred eleven trillion, seven hundred twenty-five billion, eight hundred fifty-five million, five hundred eighty-four thousand, eight hundred nine".