1323212921 has 4 divisors (see below), whose sum is σ = 1323431844. Its totient is φ = 1322994000.

The previous prime is 1323212911. The next prime is 1323212939. The reversal of 1323212921 is 1292123231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1292123231 = 7 ⋅184589033.

It can be written as a sum of positive squares in 2 ways, for example, as 501760000 + 821452921 = 22400^2 + 28661^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1323212921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1323212911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100130 + ... + 112571.

It is an arithmetic number, because the mean of its divisors is an integer number (330857961).

Almost surely, 2^1323212921 is an apocalyptic number.

It is an amenable number.

1323212921 is a deficient number, since it is larger than the sum of its proper divisors (218923).

1323212921 is an equidigital number, since it uses as much as digits as its factorization.

1323212921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218922.

The product of its digits is 1296, while the sum is 26.

The square root of 1323212921 is about 36375.9937458759. The cubic root of 1323212921 is about 1097.8506019893.

The spelling of 1323212921 in words is "one billion, three hundred twenty-three million, two hundred twelve thousand, nine hundred twenty-one".