8561011993 has 4 divisors (see below), whose sum is σ = 8577831780. Its totient is φ = 8544192208.

The previous prime is 8561011981. The next prime is 8561012059. The reversal of 8561011993 is 3991101658.

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 7234012809 + 1326999184 = 85053^2 + 36428^2 .

It is a cyclic number.

It is not a de Polignac number, because 8561011993 - 2²¹ = 8558914841 is a prime.

It is a super-3 number, since 3×8561011993³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8561011913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8409130 + ... + 8410147.

It is an arithmetic number, because the mean of its divisors is an integer number (2144457945).

Almost surely, 2^8561011993 is an apocalyptic number.

It is an amenable number.

8561011993 is a deficient number, since it is larger than the sum of its proper divisors (16819787).

8561011993 is a wasteful number, since it uses less digits than its factorization.

8561011993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16819786.

The product of its (nonzero) digits is 58320, while the sum is 43.

The square root of 8561011993 is about 92525.7369222207. The cubic root of 8561011993 is about 2045.6988537328.

The spelling of 8561011993 in words is "eight billion, five hundred sixty-one million, eleven thousand, nine hundred ninety-three".