7981563949 has 2 divisors, whose sum is σ = 7981563950. Its totient is φ = 7981563948.

The previous prime is 7981563901. The next prime is 7981563977. The reversal of 7981563949 is 9493651897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7831011049 + 150552900 = 88493^2 + 12270^2 .

It is a cyclic number.

It is not a de Polignac number, because 7981563949 - 2⁹ = 7981563437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7981563349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3990781974 + 3990781975.

It is an arithmetic number, because the mean of its divisors is an integer number (3990781975).

Almost surely, 2^7981563949 is an apocalyptic number.

It is an amenable number.

7981563949 is a deficient number, since it is larger than the sum of its proper divisors (1).

7981563949 is an equidigital number, since it uses as much as digits as its factorization.

7981563949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14696640, while the sum is 61.

The square root of 7981563949 is about 89339.5989973091. The cubic root of 7981563949 is about 1998.4624807368.

The spelling of 7981563949 in words is "seven billion, nine hundred eighty-one million, five hundred sixty-three thousand, nine hundred forty-nine".