2123405405 has 12 divisors (see below), whose sum is σ = 2800790076. Its totient is φ = 1544294400.

The previous prime is 2123405381. The next prime is 2123405429. The reversal of 2123405405 is 5045043212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2123405381) and next prime (2123405429).

It can be written as a sum of positive squares in 2 ways, for example, as 1446052729 + 677352676 = 38027^2 + 26026^2 .

It is not a de Polignac number, because 2123405405 - 2⁶ = 2123405341 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1754276 + ... + 1755485.

It is an arithmetic number, because the mean of its divisors is an integer number (233399173).

Almost surely, 2^2123405405 is an apocalyptic number.

It is an amenable number.

2123405405 is a deficient number, since it is larger than the sum of its proper divisors (677384671).

2123405405 is a wasteful number, since it uses less digits than its factorization.

2123405405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3509788 (or 3509777 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 2123405405 is about 46080.4232293932. The cubic root of 2123405405 is about 1285.3191342485.

Adding to 2123405405 its reverse (5045043212), we get a palindrome (7168448617).

The spelling of 2123405405 in words is "two billion, one hundred twenty-three million, four hundred five thousand, four hundred five".