3976776821 has 2 divisors, whose sum is σ = 3976776822. Its totient is φ = 3976776820.

The previous prime is 3976776787. The next prime is 3976776829. The reversal of 3976776821 is 1286776793.

3976776821 is digitally balanced in base 2, 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., 2630253796 + 1346523025 = 51286^2 + 36695^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3976776821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3976776829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1988388410 + 1988388411.

It is an arithmetic number, because the mean of its divisors is an integer number (1988388411).

Almost surely, 2^3976776821 is an apocalyptic number.

It is an amenable number.

3976776821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3976776821 is an equidigital number, since it uses as much as digits as its factorization.

3976776821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5334336, while the sum is 56.

The square root of 3976776821 is about 63061.6905973825. The cubic root of 3976776821 is about 1584.3230459389.

The spelling of 3976776821 in words is "three billion, nine hundred seventy-six million, seven hundred seventy-six thousand, eight hundred twenty-one".