1810194946561 has 4 divisors (see below), whose sum is σ = 1810488196692. Its totient is φ = 1809901696432.

The previous prime is 1810194946531. The next prime is 1810194946589. The reversal of 1810194946561 is 1656494910181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 83033880336 + 1727161066225 = 288156^2 + 1314215^2 .

It is a cyclic number.

It is not a de Polignac number, because 1810194946561 - 2⁷ = 1810194946433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1810194946531) 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 3 ways as a sum of consecutive naturals, for example, 146615806 + ... + 146628151.

It is an arithmetic number, because the mean of its divisors is an integer number (452622049173).

Almost surely, 2^{1810194946561} is an apocalyptic number.

It is an amenable number.

1810194946561 is a deficient number, since it is larger than the sum of its proper divisors (293250131).

1810194946561 is an equidigital number, since it uses as much as digits as its factorization.

1810194946561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293250130.

The product of its (nonzero) digits is 1866240, while the sum is 55.

The spelling of 1810194946561 in words is "one trillion, eight hundred ten billion, one hundred ninety-four million, nine hundred forty-six thousand, five hundred sixty-one".