1321204431 has 4 divisors (see below), whose sum is σ = 1761605912. Its totient is φ = 880802952.

The previous prime is 1321204411. The next prime is 1321204439. The reversal of 1321204431 is 1344021231.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1321204431 - 2¹⁷ = 1321073359 is a prime.

It is a super-2 number, since 2×1321204431² = 3491162296988067522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321204398 and 1321204407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321204439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220200736 + ... + 220200741.

It is an arithmetic number, because the mean of its divisors is an integer number (440401478).

Almost surely, 2^1321204431 is an apocalyptic number.

1321204431 is a deficient number, since it is larger than the sum of its proper divisors (440401481).

1321204431 is an equidigital number, since it uses as much as digits as its factorization.

1321204431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440401480.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 1321204431 is about 36348.3759059466. The cubic root of 1321204431 is about 1097.2948490131.

Adding to 1321204431 its reverse (1344021231), we get a palindrome (2665225662).

The spelling of 1321204431 in words is "one billion, three hundred twenty-one million, two hundred four thousand, four hundred thirty-one".