2123109091 has 2 divisors, whose sum is σ = 2123109092. Its totient is φ = 2123109090.

The previous prime is 2123109089. The next prime is 2123109097. The reversal of 2123109091 is 1909013212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2123109091 - 2¹ = 2123109089 is a prime.

Together with 2123109089, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2123109097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1061554545 + 1061554546.

It is an arithmetic number, because the mean of its divisors is an integer number (1061554546).

Almost surely, 2^2123109091 is an apocalyptic number.

2123109091 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123109091 is an equidigital number, since it uses as much as digits as its factorization.

2123109091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 2123109091 is about 46077.2079340752. The cubic root of 2123109091 is about 1285.2593441632.

The spelling of 2123109091 in words is "two billion, one hundred twenty-three million, one hundred nine thousand, ninety-one".