1311216278 has 4 divisors (see below), whose sum is σ = 1966824420. Its totient is φ = 655608138.

The previous prime is 1311216271. The next prime is 1311216281. The reversal of 1311216278 is 8726121131.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311216271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327804068 + ... + 327804071.

It is an arithmetic number, because the mean of its divisors is an integer number (491706105).

Almost surely, 2^1311216278 is an apocalyptic number.

1311216278 is a deficient number, since it is larger than the sum of its proper divisors (655608142).

1311216278 is an equidigital number, since it uses as much as digits as its factorization.

1311216278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655608141.

The product of its digits is 4032, while the sum is 32.

The square root of 1311216278 is about 36210.7204844090. The cubic root of 1311216278 is about 1094.5227107495.

The spelling of 1311216278 in words is "one billion, three hundred eleven million, two hundred sixteen thousand, two hundred seventy-eight".