9897775817 has 4 divisors (see below), whose sum is σ = 10328113920. Its totient is φ = 9467437716.

The previous prime is 9897775801. The next prime is 9897775829. The reversal of 9897775817 is 7185777989.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 9897775817 - 2⁴ = 9897775801 is a prime.

It is a super-2 number, since 2×9897775817² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9897775837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215169017 + ... + 215169062.

It is an arithmetic number, because the mean of its divisors is an integer number (2582028480).

Almost surely, 2^9897775817 is an apocalyptic number.

It is an amenable number.

9897775817 is a deficient number, since it is larger than the sum of its proper divisors (430338103).

9897775817 is a wasteful number, since it uses less digits than its factorization.

9897775817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430338102.

The product of its digits is 62233920, while the sum is 68.

The square root of 9897775817 is about 99487.5661427095. The cubic root of 9897775817 is about 2147.0683545976.

The spelling of 9897775817 in words is "nine billion, eight hundred ninety-seven million, seven hundred seventy-five thousand, eight hundred seventeen".