9771821985 has 32 divisors (see below), whose sum is σ = 15864750720. Its totient is φ = 5135356928.

The previous prime is 9771821977. The next prime is 9771822007. The reversal of 9771821985 is 5891281779.

It is a cyclic number.

It is not a de Polignac number, because 9771821985 - 2³ = 9771821977 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 474217 + ... + 494393.

It is an arithmetic number, because the mean of its divisors is an integer number (495773460).

Almost surely, 2^9771821985 is an apocalyptic number.

It is an amenable number.

9771821985 is a deficient number, since it is larger than the sum of its proper divisors (6092928735).

9771821985 is a wasteful number, since it uses less digits than its factorization.

9771821985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20657.

The product of its digits is 2540160, while the sum is 57.

The square root of 9771821985 is about 98852.5264472284. The cubic root of 9771821985 is about 2137.9219634100.

The spelling of 9771821985 in words is "nine billion, seven hundred seventy-one million, eight hundred twenty-one thousand, nine hundred eighty-five".