9999997771 has 16 divisors (see below), whose sum is σ = 10763064000. Its totient is φ = 9257591808.

The previous prime is 9999997757. The next prime is 9999997789. The reversal of 9999997771 is 1777999999.

9999997771 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9999997771 - 2²⁵ = 9966443339 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9999997171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241735 + ... + 280063.

It is an arithmetic number, because the mean of its divisors is an integer number (672691500).

Almost surely, 2^9999997771 is an apocalyptic number.

9999997771 is a deficient number, since it is larger than the sum of its proper divisors (763066229).

9999997771 is a wasteful number, since it uses less digits than its factorization.

9999997771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38598.

The product of its digits is 182284263, while the sum is 76.

The square root of 9999997771 is about 99999.9888549994. The cubic root of 9999997771 is about 2154.4345299574.

The spelling of 9999997771 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-seven thousand, seven hundred seventy-one".