1216323019 has 4 divisors (see below), whose sum is σ = 1280340040. Its totient is φ = 1152306000.

The previous prime is 1216322993. The next prime is 1216323047. The reversal of 1216323019 is 9103236121.

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 1216323019 - 2¹¹ = 1216320971 is a prime.

It is a super-2 number, since 2×1216323019² = 2958883373098548722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216323049) 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 in 3 ways as a sum of consecutive naturals, for example, 32008482 + ... + 32008519.

It is an arithmetic number, because the mean of its divisors is an integer number (320085010).

Almost surely, 2^1216323019 is an apocalyptic number.

1216323019 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1216323019 is a deficient number, since it is larger than the sum of its proper divisors (64017021).

1216323019 is an equidigital number, since it uses as much as digits as its factorization.

1216323019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64017020.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 1216323019 is about 34875.8228433395. The cubic root of 1216323019 is about 1067.4551625722.

The spelling of 1216323019 in words is "one billion, two hundred sixteen million, three hundred twenty-three thousand, nineteen".