809897993 has 8 divisors (see below), whose sum is σ = 843453000. Its totient is φ = 776718208.

The previous prime is 809897987. The next prime is 809898017. The reversal of 809897993 is 399798908.

It can be written as a sum of positive squares in 4 ways, for example, as 56505289 + 753392704 = 7517^2 + 27448^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 809897993 - 2²⁴ = 793120777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809897983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89396 + ... + 98037.

It is an arithmetic number, because the mean of its divisors is an integer number (105431625).

Almost surely, 2^809897993 is an apocalyptic number.

It is an amenable number.

809897993 is a deficient number, since it is larger than the sum of its proper divisors (33555007).

809897993 is a wasteful number, since it uses less digits than its factorization.

809897993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187611.

The product of its (nonzero) digits is 8817984, while the sum is 62.

The square root of 809897993 is about 28458.7068047724. The cubic root of 809897993 is about 932.1306193451.

The spelling of 809897993 in words is "eight hundred nine million, eight hundred ninety-seven thousand, nine hundred ninety-three".