2109758891 has 2 divisors, whose sum is σ = 2109758892. Its totient is φ = 2109758890.

The previous prime is 2109758887. The next prime is 2109758897. The reversal of 2109758891 is 1988579012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2109758891 - 2² = 2109758887 is a prime.

It is not a weakly prime, because it can be changed into another prime (2109758897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1054879445 + 1054879446.

It is an arithmetic number, because the mean of its divisors is an integer number (1054879446).

Almost surely, 2^2109758891 is an apocalyptic number.

2109758891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2109758891 is an equidigital number, since it uses as much as digits as its factorization.

2109758891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 50.

The square root of 2109758891 is about 45932.1117629050. Note that the first 3 decimals coincide. The cubic root of 2109758891 is about 1282.5597561032.

The spelling of 2109758891 in words is "two billion, one hundred nine million, seven hundred fifty-eight thousand, eight hundred ninety-one".