1216312266 has 48 divisors (see below), whose sum is σ = 2748724416. Its totient is φ = 357971328.

The previous prime is 1216312261. The next prime is 1216312267. The reversal of 1216312266 is 6622136121.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216312261) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2755 + ... + 49398.

It is an arithmetic number, because the mean of its divisors is an integer number (57265092).

Almost surely, 2^1216312266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216312266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1374362208).

1216312266 is an abundant number, since it is smaller than the sum of its proper divisors (1532412150).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216312266 is a wasteful number, since it uses less digits than its factorization.

1216312266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52207 (or 52194 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 1216312266 is about 34875.6686817615. The cubic root of 1216312266 is about 1067.4520169223.

Adding to 1216312266 its reverse (6622136121), we get a palindrome (7838448387).

The spelling of 1216312266 in words is "one billion, two hundred sixteen million, three hundred twelve thousand, two hundred sixty-six".