1321378829 has 2 divisors, whose sum is σ = 1321378830. Its totient is φ = 1321378828.

The previous prime is 1321378783. The next prime is 1321378843. The reversal of 1321378829 is 9288731231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1105230025 + 216148804 = 33245^2 + 14702^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321378829 - 2¹⁶ = 1321313293 is a prime.

It is a super-2 number, since 2×1321378829² = 3492084019458822482, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321378829.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321378229) 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 as a sum of consecutive naturals, namely, 660689414 + 660689415.

It is an arithmetic number, because the mean of its divisors is an integer number (660689415).

Almost surely, 2^1321378829 is an apocalyptic number.

It is an amenable number.

1321378829 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321378829 is an equidigital number, since it uses as much as digits as its factorization.

1321378829 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 1321378829 is about 36350.7748060478. The cubic root of 1321378829 is about 1097.3431275897.

The spelling of 1321378829 in words is "one billion, three hundred twenty-one million, three hundred seventy-eight thousand, eight hundred twenty-nine".