1321984779 has 4 divisors (see below), whose sum is σ = 1762646376. Its totient is φ = 881323184.

The previous prime is 1321984751. The next prime is 1321984789. The reversal of 1321984779 is 9774891231.

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

It is a cyclic number.

It is not a de Polignac number, because 1321984779 - 2⁵ = 1321984747 is a prime.

It is a super-3 number, since 3×1321984779³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1321984789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220330794 + ... + 220330799.

It is an arithmetic number, because the mean of its divisors is an integer number (440661594).

Almost surely, 2^1321984779 is an apocalyptic number.

1321984779 is a deficient number, since it is larger than the sum of its proper divisors (440661597).

1321984779 is an equidigital number, since it uses as much as digits as its factorization.

1321984779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440661596.

The product of its digits is 762048, while the sum is 51.

The square root of 1321984779 is about 36359.1086111857. The cubic root of 1321984779 is about 1097.5108396388.

The spelling of 1321984779 in words is "one billion, three hundred twenty-one million, nine hundred eighty-four thousand, seven hundred seventy-nine".