6644778888973 has 2 divisors, whose sum is σ = 6644778888974. Its totient is φ = 6644778888972.

The previous prime is 6644778888779. The next prime is 6644778889019. The reversal of 6644778888973 is 3798888774466.

6644778888973 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6621039167044 + 23739721929 = 2573138^2 + 154077^2 .

It is a cyclic number.

It is not a de Polignac number, because 6644778888973 - 2¹³ = 6644778880781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6644778888773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322389444486 + 3322389444487.

It is an arithmetic number, because the mean of its divisors is an integer number (3322389444487).

Almost surely, 2^{6644778888973} is an apocalyptic number.

It is an amenable number.

6644778888973 is a deficient number, since it is larger than the sum of its proper divisors (1).

6644778888973 is an equidigital number, since it uses as much as digits as its factorization.

6644778888973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21849440256, while the sum is 85.

The spelling of 6644778888973 in words is "six trillion, six hundred forty-four billion, seven hundred seventy-eight million, eight hundred eighty-eight thousand, nine hundred seventy-three".