9977997791 has 2 divisors, whose sum is σ = 9977997792. Its totient is φ = 9977997790.

The previous prime is 9977997787. The next prime is 9977997853. The reversal of 9977997791 is 1977997799.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9977997791 - 2² = 9977997787 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9977997721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4988998895 + 4988998896.

It is an arithmetic number, because the mean of its divisors is an integer number (4988998896).

Almost surely, 2^9977997791 is an apocalyptic number.

9977997791 is a deficient number, since it is larger than the sum of its proper divisors (1).

9977997791 is an equidigital number, since it uses as much as digits as its factorization.

9977997791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141776649, while the sum is 74.

The square root of 9977997791 is about 99889.9283761882. The cubic root of 9977997791 is about 2152.8534523626.

The spelling of 9977997791 in words is "nine billion, nine hundred seventy-seven million, nine hundred ninety-seven thousand, seven hundred ninety-one".