1321204031 has 4 divisors (see below), whose sum is σ = 1509947472. Its totient is φ = 1132460592.

The previous prime is 1321204013. The next prime is 1321204039. The reversal of 1321204031 is 1304021231.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321204031 is a prime.

It is a super-2 number, since 2×1321204031² = 3491160183061297922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321204039) 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, 94371710 + ... + 94371723.

It is an arithmetic number, because the mean of its divisors is an integer number (377486868).

Almost surely, 2^1321204031 is an apocalyptic number.

1321204031 is a deficient number, since it is larger than the sum of its proper divisors (188743441).

1321204031 is an equidigital number, since it uses as much as digits as its factorization.

1321204031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188743440.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1321204031 is about 36348.3704036371. The cubic root of 1321204031 is about 1097.2947382763.

Adding to 1321204031 its reverse (1304021231), we get a palindrome (2625225262).

The spelling of 1321204031 in words is "one billion, three hundred twenty-one million, two hundred four thousand, thirty-one".