2666186681 has 2 divisors, whose sum is σ = 2666186682. Its totient is φ = 2666186680.

The previous prime is 2666186591. The next prime is 2666186689. The reversal of 2666186681 is 1866816662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2666173225 + 13456 = 51635^2 + 116^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666186681 - 2¹⁰ = 2666185657 is a prime.

It is a super-2 number, since 2×2666186681² = 14217102835883591522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2666186689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333093340 + 1333093341.

It is an arithmetic number, because the mean of its divisors is an integer number (1333093341).

Almost surely, 2^2666186681 is an apocalyptic number.

It is an amenable number.

2666186681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666186681 is an equidigital number, since it uses as much as digits as its factorization.

2666186681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 995328, while the sum is 50.

The square root of 2666186681 is about 51635.1302990512. The cubic root of 2666186681 is about 1386.6393428405.

The spelling of 2666186681 in words is "two billion, six hundred sixty-six million, one hundred eighty-six thousand, six hundred eighty-one".