1813531689 has 24 divisors (see below), whose sum is σ = 2647948680. Its totient is φ = 1195955712.

The previous prime is 1813531673. The next prime is 1813531697. The reversal of 1813531689 is 9861353181.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 15093225 + 1798438464 = 3885^2 + 42408^2 .

It is not a de Polignac number, because 1813531689 - 2⁴ = 1813531673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1813531619) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 621967 + ... + 624875.

It is an arithmetic number, because the mean of its divisors is an integer number (110331195).

Almost surely, 2^1813531689 is an apocalyptic number.

It is an amenable number.

1813531689 is a deficient number, since it is larger than the sum of its proper divisors (834416991).

1813531689 is a wasteful number, since it uses less digits than its factorization.

1813531689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3641 (or 3638 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 1813531689 is about 42585.5807639159. The cubic root of 1813531689 is about 1219.4810318462.

The spelling of 1813531689 in words is "one billion, eight hundred thirteen million, five hundred thirty-one thousand, six hundred eighty-nine".