7777421856887 has 2 divisors, whose sum is σ = 7777421856888. Its totient is φ = 7777421856886.

The previous prime is 7777421856847. The next prime is 7777421856929. The reversal of 7777421856887 is 7886581247777.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 7777421856887 - 2¹² = 7777421852791 is a prime.

It is a super-2 number, since 2×7777421856887² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7777421856817) 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 as a sum of consecutive naturals, namely, 3888710928443 + 3888710928444.

It is an arithmetic number, because the mean of its divisors is an integer number (3888710928444).

Almost surely, 2^{7777421856887} is an apocalyptic number.

7777421856887 is a deficient number, since it is larger than the sum of its proper divisors (1).

7777421856887 is an equidigital number, since it uses as much as digits as its factorization.

7777421856887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2065244160, while the sum is 77.

The spelling of 7777421856887 in words is "seven trillion, seven hundred seventy-seven billion, four hundred twenty-one million, eight hundred fifty-six thousand, eight hundred eighty-seven".