813555745 has 4 divisors (see below), whose sum is σ = 976266900. Its totient is φ = 650844592.

The previous prime is 813555733. The next prime is 813555749. The reversal of 813555745 is 547555318.

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 425308129 + 388247616 = 20623^2 + 19704^2 .

It is a cyclic number.

It is not a de Polignac number, because 813555745 - 2⁵ = 813555713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (813555749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81355570 + ... + 81355579.

It is an arithmetic number, because the mean of its divisors is an integer number (244066725).

Almost surely, 2^813555745 is an apocalyptic number.

It is an amenable number.

813555745 is a deficient number, since it is larger than the sum of its proper divisors (162711155).

813555745 is a wasteful number, since it uses less digits than its factorization.

813555745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162711154.

The product of its digits is 420000, while the sum is 43.

The square root of 813555745 is about 28522.8986079606. The cubic root of 813555745 is about 933.5317763278.

The spelling of 813555745 in words is "eight hundred thirteen million, five hundred fifty-five thousand, seven hundred forty-five".