61116664681 has 2 divisors, whose sum is σ = 61116664682. Its totient is φ = 61116664680.

The previous prime is 61116664673. The next prime is 61116664729. The reversal of 61116664681 is 18646661116.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39424088025 + 21692576656 = 198555^2 + 147284^2 .

It is a cyclic number.

It is not a de Polignac number, because 61116664681 - 2³ = 61116664673 is a prime.

It is a super-4 number, since 4×61116664681⁴ (a number of 44 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (61116664981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30558332340 + 30558332341.

It is an arithmetic number, because the mean of its divisors is an integer number (30558332341).

Almost surely, 2^61116664681 is an apocalyptic number.

It is an amenable number.

61116664681 is a deficient number, since it is larger than the sum of its proper divisors (1).

61116664681 is an equidigital number, since it uses as much as digits as its factorization.

61116664681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The spelling of 61116664681 in words is "sixty-one billion, one hundred sixteen million, six hundred sixty-four thousand, six hundred eighty-one".