7772887981 has 2 divisors, whose sum is σ = 7772887982. Its totient is φ = 7772887980.

The previous prime is 7772887979. The next prime is 7772888003. The reversal of 7772887981 is 1897882777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4871342025 + 2901545956 = 69795^2 + 53866^2 .

It is a cyclic number.

It is not a de Polignac number, because 7772887981 - 2¹ = 7772887979 is a prime.

It is a super-2 number, since 2×7772887981² (a number of 21 digits) contains 22 as substring.

Together with 7772887979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7772887901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3886443990 + 3886443991.

It is an arithmetic number, because the mean of its divisors is an integer number (3886443991).

Almost surely, 2^7772887981 is an apocalyptic number.

It is an amenable number.

7772887981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7772887981 is an equidigital number, since it uses as much as digits as its factorization.

7772887981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22127616, while the sum is 64.

The square root of 7772887981 is about 88163.9834683075. The cubic root of 7772887981 is about 1980.8920223964.

The spelling of 7772887981 in words is "seven billion, seven hundred seventy-two million, eight hundred eighty-seven thousand, nine hundred eighty-one".