2078187691 has 2 divisors, whose sum is σ = 2078187692. Its totient is φ = 2078187690.

The previous prime is 2078187653. The next prime is 2078187707. The reversal of 2078187691 is 1967818702.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2078187691 is a prime.

It is a super-2 number, since 2×2078187691² = 8637728158047822962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2078187091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1039093845 + 1039093846.

It is an arithmetic number, because the mean of its divisors is an integer number (1039093846).

Almost surely, 2^2078187691 is an apocalyptic number.

2078187691 is a deficient number, since it is larger than the sum of its proper divisors (1).

2078187691 is an equidigital number, since it uses as much as digits as its factorization.

2078187691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 338688, while the sum is 49.

The square root of 2078187691 is about 45587.1439223823. The cubic root of 2078187691 is about 1276.1300126219.

The spelling of 2078187691 in words is "two billion, seventy-eight million, one hundred eighty-seven thousand, six hundred ninety-one".