6644577785387 has 2 divisors, whose sum is σ = 6644577785388. Its totient is φ = 6644577785386.

The previous prime is 6644577785353. The next prime is 6644577785473. The reversal of 6644577785387 is 7835877754466.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6644577785387 - 2²² = 6644573591083 is a prime.

It is not a weakly prime, because it can be changed into another prime (6644577785327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322288892693 + 3322288892694.

It is an arithmetic number, because the mean of its divisors is an integer number (3322288892694).

Almost surely, 2^{6644577785387} is an apocalyptic number.

6644577785387 is a deficient number, since it is larger than the sum of its proper divisors (1).

6644577785387 is an equidigital number, since it uses as much as digits as its factorization.

6644577785387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6638284800, while the sum is 77.

The spelling of 6644577785387 in words is "six trillion, six hundred forty-four billion, five hundred seventy-seven million, seven hundred eighty-five thousand, three hundred eighty-seven".