2123240021 has 12 divisors (see below), whose sum is σ = 2511757440. Its totient is φ = 1789071480.

The previous prime is 2123239969. The next prime is 2123240023. The reversal of 2123240021 is 1200423212.

It is not a de Polignac number, because 2123240021 - 2⁶ = 2123239957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123240023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 364325 + ... + 370106.

It is an arithmetic number, because the mean of its divisors is an integer number (209313120).

Almost surely, 2^2123240021 is an apocalyptic number.

It is an amenable number.

2123240021 is a deficient number, since it is larger than the sum of its proper divisors (388517419).

2123240021 is an equidigital number, since it uses as much as digits as its factorization.

2123240021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 734504 (or 734497 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 2123240021 is about 46078.6286796819. The cubic root of 2123240021 is about 1285.2857638367.

Adding to 2123240021 its reverse (1200423212), we get a palindrome (3323663233).

The spelling of 2123240021 in words is "two billion, one hundred twenty-three million, two hundred forty thousand, twenty-one".