2660611661 has 2 divisors, whose sum is σ = 2660611662. Its totient is φ = 2660611660.

The previous prime is 2660611637. The next prime is 2660611663. The reversal of 2660611661 is 1661160662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2660599561 + 12100 = 51581^2 + 110^2 .

It is a cyclic number.

It is not a de Polignac number, because 2660611661 - 2¹⁰ = 2660610637 is a prime.

Together with 2660611663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2660611663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330305830 + 1330305831.

It is an arithmetic number, because the mean of its divisors is an integer number (1330305831).

Almost surely, 2^2660611661 is an apocalyptic number.

It is an amenable number.

2660611661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2660611661 is an equidigital number, since it uses as much as digits as its factorization.

2660611661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 2660611661 is about 51581.1172911173. The cubic root of 2660611661 is about 1385.6721766873.

The spelling of 2660611661 in words is "two billion, six hundred sixty million, six hundred eleven thousand, six hundred sixty-one".