61613431106681 has 2 divisors, whose sum is σ = 61613431106682. Its totient is φ = 61613431106680.

The previous prime is 61613431106641. The next prime is 61613431106683. The reversal of 61613431106681 is 18660113431616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43510065518656 + 18103365588025 = 6596216^2 + 4254805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61613431106681 is a prime.

It is a super-2 number, since 2×61613431106681² (a number of 28 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 61613431106683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (61613431106683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30806715553340 + 30806715553341.

It is an arithmetic number, because the mean of its divisors is an integer number (30806715553341).

Almost surely, 2^{61613431106681} is an apocalyptic number.

It is an amenable number.

61613431106681 is a deficient number, since it is larger than the sum of its proper divisors (1).

61613431106681 is an equidigital number, since it uses as much as digits as its factorization.

61613431106681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 47.

The spelling of 61613431106681 in words is "sixty-one trillion, six hundred thirteen billion, four hundred thirty-one million, one hundred six thousand, six hundred eighty-one".