61816117787 has 2 divisors, whose sum is σ = 61816117788. Its totient is φ = 61816117786.

The previous prime is 61816117771. The next prime is 61816117873. The reversal of 61816117787 is 78771161816.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61816117787 - 2⁴ = 61816117771 is a prime.

It is not a weakly prime, because it can be changed into another prime (61816117747) 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, 30908058893 + 30908058894.

It is an arithmetic number, because the mean of its divisors is an integer number (30908058894).

Almost surely, 2^61816117787 is an apocalyptic number.

61816117787 is a deficient number, since it is larger than the sum of its proper divisors (1).

61816117787 is an equidigital number, since it uses as much as digits as its factorization.

61816117787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 790272, while the sum is 53.

The spelling of 61816117787 in words is "sixty-one billion, eight hundred sixteen million, one hundred seventeen thousand, seven hundred eighty-seven".