981776993 has 2 divisors, whose sum is σ = 981776994. Its totient is φ = 981776992.

The previous prime is 981776977. The next prime is 981777053. The reversal of 981776993 is 399677189.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 928603729 + 53173264 = 30473^2 + 7292^2 .

It is an emirp because it is prime and its reverse (399677189) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 981776993 - 2⁴ = 981776977 is a prime.

It is not a weakly prime, because it can be changed into another prime (981776923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490888496 + 490888497.

It is an arithmetic number, because the mean of its divisors is an integer number (490888497).

Almost surely, 2^981776993 is an apocalyptic number.

It is an amenable number.

981776993 is a deficient number, since it is larger than the sum of its proper divisors (1).

981776993 is an equidigital number, since it uses as much as digits as its factorization.

981776993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5143824, while the sum is 59.

The square root of 981776993 is about 31333.3208102812. The cubic root of 981776993 is about 993.8883886330. Note that the first 3 decimals are identical.

The spelling of 981776993 in words is "nine hundred eighty-one million, seven hundred seventy-six thousand, nine hundred ninety-three".