9904955861 has 4 divisors (see below), whose sum is σ = 9905154924. Its totient is φ = 9904756800.

The previous prime is 9904955857. The next prime is 9904955869. The reversal of 9904955861 is 1685594099.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7230100900 + 2674854961 = 85030^2 + 51719^2 .

It is a cyclic number.

It is not a de Polignac number, because 9904955861 - 2² = 9904955857 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9904955797 and 9904955806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9904955869) 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, 47951 + ... + 148691.

It is an arithmetic number, because the mean of its divisors is an integer number (2476288731).

Almost surely, 2^9904955861 is an apocalyptic number.

It is an amenable number.

9904955861 is a deficient number, since it is larger than the sum of its proper divisors (199063).

9904955861 is a wasteful number, since it uses less digits than its factorization.

9904955861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199062.

The product of its (nonzero) digits is 3499200, while the sum is 56.

The square root of 9904955861 is about 99523.6447332994. The cubic root of 9904955861 is about 2147.5874045115.

The spelling of 9904955861 in words is "nine billion, nine hundred four million, nine hundred fifty-five thousand, eight hundred sixty-one".