1216831273 has 4 divisors (see below), whose sum is σ = 1390664320. Its totient is φ = 1042998228.

The previous prime is 1216831267. The next prime is 1216831277. The reversal of 1216831273 is 3721386121.

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 not a de Polignac number, because 1216831273 - 2⁵ = 1216831241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216831277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86916513 + ... + 86916526.

It is an arithmetic number, because the mean of its divisors is an integer number (347666080).

Almost surely, 2^1216831273 is an apocalyptic number.

It is an amenable number.

1216831273 is a deficient number, since it is larger than the sum of its proper divisors (173833047).

1216831273 is an equidigital number, since it uses as much as digits as its factorization.

1216831273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173833046.

The product of its digits is 12096, while the sum is 34.

The square root of 1216831273 is about 34883.1087060772. The cubic root of 1216831273 is about 1067.6038245084.

The spelling of 1216831273 in words is "one billion, two hundred sixteen million, eight hundred thirty-one thousand, two hundred seventy-three".