1321403021 has 4 divisors (see below), whose sum is σ = 1329509952. Its totient is φ = 1313296092.

The previous prime is 1321402933. The next prime is 1321403023. The reversal of 1321403021 is 1203041231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321403021 is a prime.

It is a super-2 number, since 2×1321403021² = 3492211887815852882, 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 (1321403023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4053221 + ... + 4053546.

It is an arithmetic number, because the mean of its divisors is an integer number (332377488).

Almost surely, 2^1321403021 is an apocalyptic number.

It is an amenable number.

1321403021 is a deficient number, since it is larger than the sum of its proper divisors (8106931).

1321403021 is an equidigital number, since it uses as much as digits as its factorization.

1321403021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8106930.

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

The square root of 1321403021 is about 36351.1075622188. The cubic root of 1321403021 is about 1097.3498243225.

Adding to 1321403021 its reverse (1203041231), we get a palindrome (2524444252).

The spelling of 1321403021 in words is "one billion, three hundred twenty-one million, four hundred three thousand, twenty-one".