7766776421 has 2 divisors, whose sum is σ = 7766776422. Its totient is φ = 7766776420.

The previous prime is 7766776397. The next prime is 7766776481. The reversal of 7766776421 is 1246776677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5492440321 + 2274336100 = 74111^2 + 47690^2 .

It is a cyclic number.

It is not a de Polignac number, because 7766776421 - 2³⁰ = 6693034597 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7766776481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3883388210 + 3883388211.

It is an arithmetic number, because the mean of its divisors is an integer number (3883388211).

Almost surely, 2^7766776421 is an apocalyptic number.

It is an amenable number.

7766776421 is a deficient number, since it is larger than the sum of its proper divisors (1).

7766776421 is an equidigital number, since it uses as much as digits as its factorization.

7766776421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4148928, while the sum is 53.

The square root of 7766776421 is about 88129.3164673368. The cubic root of 7766776421 is about 1980.3727167106.

The spelling of 7766776421 in words is "seven billion, seven hundred sixty-six million, seven hundred seventy-six thousand, four hundred twenty-one".