75643787561 has 2 divisors, whose sum is σ = 75643787562. Its totient is φ = 75643787560.

The previous prime is 75643787509. The next prime is 75643787657. The reversal of 75643787561 is 16578734657.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74068888336 + 1574899225 = 272156^2 + 39685^2 .

It is a cyclic number.

It is not a de Polignac number, because 75643787561 - 2²² = 75639593257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 75643787561.

It is not a weakly prime, because it can be changed into another prime (75643787501) 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, 37821893780 + 37821893781.

It is an arithmetic number, because the mean of its divisors is an integer number (37821893781).

Almost surely, 2^75643787561 is an apocalyptic number.

It is an amenable number.

75643787561 is a deficient number, since it is larger than the sum of its proper divisors (1).

75643787561 is an equidigital number, since it uses as much as digits as its factorization.

75643787561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29635200, while the sum is 59.

The spelling of 75643787561 in words is "seventy-five billion, six hundred forty-three million, seven hundred eighty-seven thousand, five hundred sixty-one".