2611678661 has 2 divisors, whose sum is σ = 2611678662. Its totient is φ = 2611678660.

The previous prime is 2611678621. The next prime is 2611678691. The reversal of 2611678661 is 1668761162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2543285761 + 68392900 = 50431^2 + 8270^2 .

It is a cyclic number.

It is not a de Polignac number, because 2611678661 - 2¹⁰ = 2611677637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2611678621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1305839330 + 1305839331.

It is an arithmetic number, because the mean of its divisors is an integer number (1305839331).

Almost surely, 2^2611678661 is an apocalyptic number.

It is an amenable number.

2611678661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2611678661 is an equidigital number, since it uses as much as digits as its factorization.

2611678661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 2611678661 is about 51104.5855183270. The cubic root of 2611678661 is about 1377.1246335436.

The spelling of 2611678661 in words is "two billion, six hundred eleven million, six hundred seventy-eight thousand, six hundred sixty-one".