1321443251 has 2 divisors, whose sum is σ = 1321443252. Its totient is φ = 1321443250.

The previous prime is 1321443209. The next prime is 1321443257. The reversal of 1321443251 is 1523441231.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321443251 is a prime.

It is a super-2 number, since 2×1321443251² = 3492424531226898002, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321443251.

It is not a weakly prime, because it can be changed into another prime (1321443257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660721625 + 660721626.

It is an arithmetic number, because the mean of its divisors is an integer number (660721626).

Almost surely, 2^1321443251 is an apocalyptic number.

1321443251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321443251 is an equidigital number, since it uses as much as digits as its factorization.

1321443251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 26.

The square root of 1321443251 is about 36351.6609111606. The cubic root of 1321443251 is about 1097.3609604494.

Adding to 1321443251 its reverse (1523441231), we get a palindrome (2844884482).

It can be divided in two parts, 13214 and 43251, that added together give a palindrome (56465).

The spelling of 1321443251 in words is "one billion, three hundred twenty-one million, four hundred forty-three thousand, two hundred fifty-one".