61087921717 has 2 divisors, whose sum is σ = 61087921718. Its totient is φ = 61087921716.

The previous prime is 61087921709. The next prime is 61087921729. The reversal of 61087921717 is 71712978016.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59110251876 + 1977669841 = 243126^2 + 44471^2 .

It is a cyclic number.

It is not a de Polignac number, because 61087921717 - 2³ = 61087921709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61087921217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30543960858 + 30543960859.

It is an arithmetic number, because the mean of its divisors is an integer number (30543960859).

Almost surely, 2^61087921717 is an apocalyptic number.

It is an amenable number.

61087921717 is a deficient number, since it is larger than the sum of its proper divisors (1).

61087921717 is an equidigital number, since it uses as much as digits as its factorization.

61087921717 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 296352, while the sum is 49.

The spelling of 61087921717 in words is "sixty-one billion, eighty-seven million, nine hundred twenty-one thousand, seven hundred seventeen".