61447561771 has 2 divisors, whose sum is σ = 61447561772. Its totient is φ = 61447561770.

The previous prime is 61447561711. The next prime is 61447561787. The reversal of 61447561771 is 17716574416.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61447561771 is a prime.

It is not a weakly prime, because it can be changed into another prime (61447561711) 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, 30723780885 + 30723780886.

It is an arithmetic number, because the mean of its divisors is an integer number (30723780886).

Almost surely, 2^61447561771 is an apocalyptic number.

61447561771 is a deficient number, since it is larger than the sum of its proper divisors (1).

61447561771 is an equidigital number, since it uses as much as digits as its factorization.

61447561771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 987840, while the sum is 49.

The spelling of 61447561771 in words is "sixty-one billion, four hundred forty-seven million, five hundred sixty-one thousand, seven hundred seventy-one".