1166601055681 has 2 divisors, whose sum is σ = 1166601055682. Its totient is φ = 1166601055680.

The previous prime is 1166601055589. The next prime is 1166601055703. The reversal of 1166601055681 is 1865501066611.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 902832530625 + 263768525056 = 950175^2 + 513584^2 .

It is a cyclic number.

It is not a de Polignac number, because 1166601055681 - 2¹⁷ = 1166600924609 is a prime.

It is a super-2 number, since 2×1166601055681² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1166601055981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 583300527840 + 583300527841.

It is an arithmetic number, because the mean of its divisors is an integer number (583300527841).

Almost surely, 2^{1166601055681} is an apocalyptic number.

It is an amenable number.

1166601055681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1166601055681 is an equidigital number, since it uses as much as digits as its factorization.

1166601055681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 46.

The spelling of 1166601055681 in words is "one trillion, one hundred sixty-six billion, six hundred one million, fifty-five thousand, six hundred eighty-one".