1813213585 has 4 divisors (see below), whose sum is σ = 2175856308. Its totient is φ = 1450570864.

The previous prime is 1813213559. The next prime is 1813213607. The reversal of 1813213585 is 5853123181.

It is a happy number.

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 1157904784 + 655308801 = 34028^2 + 25599^2 .

It is a cyclic number.

It is not a de Polignac number, because 1813213585 - 2¹⁹ = 1812689297 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181321354 + ... + 181321363.

It is an arithmetic number, because the mean of its divisors is an integer number (543964077).

Almost surely, 2^1813213585 is an apocalyptic number.

It is an amenable number.

1813213585 is a deficient number, since it is larger than the sum of its proper divisors (362642723).

1813213585 is an equidigital number, since it uses as much as digits as its factorization.

1813213585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362642722.

The product of its digits is 28800, while the sum is 37.

The square root of 1813213585 is about 42581.8457209173. The cubic root of 1813213585 is about 1219.4097263230.

The spelling of 1813213585 in words is "one billion, eight hundred thirteen million, two hundred thirteen thousand, five hundred eighty-five".