2666694661 has 2 divisors, whose sum is σ = 2666694662. Its totient is φ = 2666694660.

The previous prime is 2666694587. The next prime is 2666694677. The reversal of 2666694661 is 1664966662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2522550625 + 144144036 = 50225^2 + 12006^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666694661 - 2¹³ = 2666686469 is a prime.

It is a super-2 number, since 2×2666694661² = 14222520830011809842, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2666694599 and 2666694608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2666694461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333347330 + 1333347331.

It is an arithmetic number, because the mean of its divisors is an integer number (1333347331).

Almost surely, 2^2666694661 is an apocalyptic number.

It is an amenable number.

2666694661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666694661 is an equidigital number, since it uses as much as digits as its factorization.

2666694661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3359232, while the sum is 52.

The square root of 2666694661 is about 51640.0490026878. The cubic root of 2666694661 is about 1386.7274012309.

The spelling of 2666694661 in words is "two billion, six hundred sixty-six million, six hundred ninety-four thousand, six hundred sixty-one".