2121123405 has 32 divisors (see below), whose sum is σ = 3642689664. Its totient is φ = 1050126336.

The previous prime is 2121123391. The next prime is 2121123413. The reversal of 2121123405 is 5043211212.

It is not a de Polignac number, because 2121123405 - 2⁶ = 2121123341 is a prime.

It is a congruent number.

It is an unprimeable number.

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 in 31 ways as a sum of consecutive naturals, for example, 38359 + ... + 75588.

It is an arithmetic number, because the mean of its divisors is an integer number (113834052).

Almost surely, 2^2121123405 is an apocalyptic number.

It is an amenable number.

2121123405 is a deficient number, since it is larger than the sum of its proper divisors (1521566259).

2121123405 is a wasteful number, since it uses less digits than its factorization.

2121123405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114045.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 2121123405 is about 46055.6555159081. The cubic root of 2121123405 is about 1284.8585298490.

Adding to 2121123405 its reverse (5043211212), we get a palindrome (7164334617).

The spelling of 2121123405 in words is "two billion, one hundred twenty-one million, one hundred twenty-three thousand, four hundred five".