617778888889 has 4 divisors (see below), whose sum is σ = 617788532980. Its totient is φ = 617769244800.

The previous prime is 617778888851. The next prime is 617778888907. The reversal of 617778888889 is 988888877716.

It is a happy number.

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 548796492864 + 68982396025 = 740808^2 + 262645^2 .

It is a cyclic number.

It is not a de Polignac number, because 617778888889 - 2¹¹ = 617778886841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (617778888589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4725312 + ... + 4854289.

It is an arithmetic number, because the mean of its divisors is an integer number (154447133245).

Almost surely, 2^617778888889 is an apocalyptic number.

It is an amenable number.

617778888889 is a deficient number, since it is larger than the sum of its proper divisors (9644091).

617778888889 is an equidigital number, since it uses as much as digits as its factorization.

617778888889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9644090.

The product of its digits is 4855431168, while the sum is 85.

The spelling of 617778888889 in words is "six hundred seventeen billion, seven hundred seventy-eight million, eight hundred eighty-eight thousand, eight hundred eighty-nine".