2126209905 has 24 divisors (see below), whose sum is σ = 3821930112. Its totient is φ = 1133977968.

The previous prime is 2126209901. The next prime is 2126209933. The reversal of 2126209905 is 5099026212.

It is a happy number.

2126209905 is a `hidden beast` number, since 21 + 2 + 620 + 9 + 9 + 0 + 5 = 666.

It is not a de Polignac number, because 2126209905 - 2² = 2126209901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2126209905.

It is not an unprimeable number, because it can be changed into a prime (2126209901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 873769 + ... + 876198.

It is an arithmetic number, because the mean of its divisors is an integer number (159247088).

Almost surely, 2^2126209905 is an apocalyptic number.

It is an amenable number.

2126209905 is a deficient number, since it is larger than the sum of its proper divisors (1695720207).

2126209905 is an equidigital number, since it uses as much as digits as its factorization.

2126209905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1749987 (or 1749975 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 2126209905 is about 46110.8436812861. The cubic root of 2126209905 is about 1285.8847495413.

The spelling of 2126209905 in words is "two billion, one hundred twenty-six million, two hundred nine thousand, nine hundred five".