61712991161 has 2 divisors, whose sum is σ = 61712991162. Its totient is φ = 61712991160.

The previous prime is 61712991107. The next prime is 61712991169. The reversal of 61712991161 is 16119921716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36417997225 + 25294993936 = 190835^2 + 159044^2 .

It is a cyclic number.

It is not a de Polignac number, because 61712991161 - 2¹⁸ = 61712729017 is a prime.

It is not a weakly prime, because it can be changed into another prime (61712991169) 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, 30856495580 + 30856495581.

It is an arithmetic number, because the mean of its divisors is an integer number (30856495581).

Almost surely, 2^61712991161 is an apocalyptic number.

It is an amenable number.

61712991161 is a deficient number, since it is larger than the sum of its proper divisors (1).

61712991161 is an equidigital number, since it uses as much as digits as its factorization.

61712991161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 44.

The spelling of 61712991161 in words is "sixty-one billion, seven hundred twelve million, nine hundred ninety-one thousand, one hundred sixty-one".