9855812661 has 8 divisors (see below), whose sum is σ = 13594224480. Its totient is φ = 6343971312.

The previous prime is 9855812657. The next prime is 9855812669. The reversal of 9855812661 is 1662185589.

9855812661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 9855812661 - 2² = 9855812657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9855812669) 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 7 ways as a sum of consecutive naturals, for example, 56642515 + ... + 56642688.

It is an arithmetic number, because the mean of its divisors is an integer number (1699278060).

Almost surely, 2^9855812661 is an apocalyptic number.

It is an amenable number.

9855812661 is a deficient number, since it is larger than the sum of its proper divisors (3738411819).

9855812661 is a wasteful number, since it uses less digits than its factorization.

9855812661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113285235.

The product of its digits is 1036800, while the sum is 51.

The square root of 9855812661 is about 99276.4456505167. The cubic root of 9855812661 is about 2144.0297799203.

The spelling of 9855812661 in words is "nine billion, eight hundred fifty-five million, eight hundred twelve thousand, six hundred sixty-one".