1216631105 has 4 divisors (see below), whose sum is σ = 1459957332. Its totient is φ = 973304880.

The previous prime is 1216631063. The next prime is 1216631131. The reversal of 1216631105 is 5011366121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5011366121 = 23827 ⋅210323.

It can be written as a sum of positive squares in 2 ways, for example, as 799532176 + 417098929 = 28276^2 + 20423^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1216631105 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121663106 + ... + 121663115.

It is an arithmetic number, because the mean of its divisors is an integer number (364989333).

Almost surely, 2^1216631105 is an apocalyptic number.

It is an amenable number.

1216631105 is a deficient number, since it is larger than the sum of its proper divisors (243326227).

1216631105 is an equidigital number, since it uses as much as digits as its factorization.

1216631105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243326226.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1216631105 is about 34880.2394630541. The cubic root of 1216631105 is about 1067.5452812395.

Adding to 1216631105 its reverse (5011366121), we get a palindrome (6227997226).

The spelling of 1216631105 in words is "one billion, two hundred sixteen million, six hundred thirty-one thousand, one hundred five".