7949137561 has 2 divisors, whose sum is σ = 7949137562. Its totient is φ = 7949137560.

The previous prime is 7949137549. The next prime is 7949137577. The reversal of 7949137561 is 1657319497.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7431302025 + 517835536 = 86205^2 + 22756^2 .

It is an emirp because it is prime and its reverse (1657319497) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7949137561 - 2²³ = 7940748953 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7949137499 and 7949137508.

It is not a weakly prime, because it can be changed into another prime (7949137541) 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, 3974568780 + 3974568781.

It is an arithmetic number, because the mean of its divisors is an integer number (3974568781).

Almost surely, 2^7949137561 is an apocalyptic number.

It is an amenable number.

7949137561 is a deficient number, since it is larger than the sum of its proper divisors (1).

7949137561 is an equidigital number, since it uses as much as digits as its factorization.

7949137561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1428840, while the sum is 52.

The square root of 7949137561 is about 89157.9360517055. The cubic root of 7949137561 is about 1995.7524489578.

The spelling of 7949137561 in words is "seven billion, nine hundred forty-nine million, one hundred thirty-seven thousand, five hundred sixty-one".