2789256661 has 2 divisors, whose sum is σ = 2789256662. Its totient is φ = 2789256660.

The previous prime is 2789256649. The next prime is 2789256721. The reversal of 2789256661 is 1666529872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1674364561 + 1114892100 = 40919^2 + 33390^2 .

It is a cyclic number.

It is not a de Polignac number, because 2789256661 - 2⁵ = 2789256629 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2789256599 and 2789256608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2789256461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1394628330 + 1394628331.

It is an arithmetic number, because the mean of its divisors is an integer number (1394628331).

Almost surely, 2^2789256661 is an apocalyptic number.

It is an amenable number.

2789256661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2789256661 is an equidigital number, since it uses as much as digits as its factorization.

2789256661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2177280, while the sum is 52.

The square root of 2789256661 is about 52813.4136465349. The cubic root of 2789256661 is about 1407.6547807241.

The spelling of 2789256661 in words is "two billion, seven hundred eighty-nine million, two hundred fifty-six thousand, six hundred sixty-one".