3994559561 has 8 divisors (see below), whose sum is σ = 4004292864. Its totient is φ = 3984837840.

The previous prime is 3994559549. The next prime is 3994559599. The reversal of 3994559561 is 1659554993.

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

It is a cyclic number.

It is not a de Polignac number, because 3994559561 - 2²² = 3990365257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3994559497 and 3994559506.

It is not an unprimeable number, because it can be changed into a prime (3994559501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1346666 + ... + 1349628.

It is an arithmetic number, because the mean of its divisors is an integer number (500536608).

Almost surely, 2^3994559561 is an apocalyptic number.

It is an amenable number.

3994559561 is a deficient number, since it is larger than the sum of its proper divisors (9733303).

3994559561 is a wasteful number, since it uses less digits than its factorization.

3994559561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5791.

The product of its digits is 6561000, while the sum is 56.

The square root of 3994559561 is about 63202.5281219035. The cubic root of 3994559561 is about 1586.6810455576.

The spelling of 3994559561 in words is "three billion, nine hundred ninety-four million, five hundred fifty-nine thousand, five hundred sixty-one".