5136661561 has 2 divisors, whose sum is σ = 5136661562. Its totient is φ = 5136661560.

The previous prime is 5136661559. The next prime is 5136661577. The reversal of 5136661561 is 1651666315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4505094400 + 631567161 = 67120^2 + 25131^2 .

It is a cyclic number.

It is not a de Polignac number, because 5136661561 - 2¹ = 5136661559 is a prime.

Together with 5136661559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (5136661531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2568330780 + 2568330781.

It is an arithmetic number, because the mean of its divisors is an integer number (2568330781).

Almost surely, 2^5136661561 is an apocalyptic number.

It is an amenable number.

5136661561 is a deficient number, since it is larger than the sum of its proper divisors (1).

5136661561 is an equidigital number, since it uses as much as digits as its factorization.

5136661561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 40.

The square root of 5136661561 is about 71670.5069118393. The cubic root of 5136661561 is about 1725.4153237581.

The spelling of 5136661561 in words is "five billion, one hundred thirty-six million, six hundred sixty-one thousand, five hundred sixty-one".