2123212321 has 4 divisors (see below), whose sum is σ = 2123305492. Its totient is φ = 2123119152.

The previous prime is 2123212319. The next prime is 2123212337. The reversal of 2123212321 is 1232123212.

2123212321 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1735555600 + 387656721 = 41660^2 + 19689^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123212321 - 2¹ = 2123212319 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2123212381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13015 + ... + 66451.

It is an arithmetic number, because the mean of its divisors is an integer number (530826373).

Almost surely, 2^2123212321 is an apocalyptic number.

It is an amenable number.

2123212321 is a deficient number, since it is larger than the sum of its proper divisors (93171).

2123212321 is an equidigital number, since it uses as much as digits as its factorization.

2123212321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93170.

The product of its digits is 288, while the sum is 19.

The square root of 2123212321 is about 46078.3281055205. The cubic root of 2123212321 is about 1285.2801744905.

Adding to 2123212321 its reverse (1232123212), we get a palindrome (3355335533).

It can be divided in two parts, 2 and 123212321, that multiplied together give a palindrome (246424642).

The spelling of 2123212321 in words is "two billion, one hundred twenty-three million, two hundred twelve thousand, three hundred twenty-one".