2606781857 has 2 divisors, whose sum is σ = 2606781858. Its totient is φ = 2606781856.

The previous prime is 2606781851. The next prime is 2606781923. The reversal of 2606781857 is 7581876062.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2606000401 + 781456 = 51049^2 + 884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2606781857 is a prime.

It is not a weakly prime, because it can be changed into another prime (2606781851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1303390928 + 1303390929.

It is an arithmetic number, because the mean of its divisors is an integer number (1303390929).

Almost surely, 2^2606781857 is an apocalyptic number.

It is an amenable number.

2606781857 is a deficient number, since it is larger than the sum of its proper divisors (1).

2606781857 is an equidigital number, since it uses as much as digits as its factorization.

2606781857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 50.

The square root of 2606781857 is about 51056.6534058001. The cubic root of 2606781857 is about 1376.2634086000.

The spelling of 2606781857 in words is "two billion, six hundred six million, seven hundred eighty-one thousand, eight hundred fifty-seven".