2109128591 has 2 divisors, whose sum is σ = 2109128592. Its totient is φ = 2109128590.

The previous prime is 2109128509. The next prime is 2109128597. The reversal of 2109128591 is 1958219012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2109128591 - 2³⁰ = 1035386767 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2109128597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1054564295 + 1054564296.

It is an arithmetic number, because the mean of its divisors is an integer number (1054564296).

Almost surely, 2^2109128591 is an apocalyptic number.

2109128591 is a deficient number, since it is larger than the sum of its proper divisors (1).

2109128591 is an equidigital number, since it uses as much as digits as its factorization.

2109128591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 38.

The square root of 2109128591 is about 45925.2500374249. The cubic root of 2109128591 is about 1282.4320198747.

The spelling of 2109128591 in words is "two billion, one hundred nine million, one hundred twenty-eight thousand, five hundred ninety-one".