1216511634 has 16 divisors (see below), whose sum is σ = 2620179072. Its totient is φ = 374311248.

The previous prime is 1216511623. The next prime is 1216511693. The reversal of 1216511634 is 4361156121.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7798074 + ... + 7798229.

It is an arithmetic number, because the mean of its divisors is an integer number (163761192).

Almost surely, 2^1216511634 is an apocalyptic number.

1216511634 is an abundant number, since it is smaller than the sum of its proper divisors (1403667438).

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

1216511634 is a wasteful number, since it uses less digits than its factorization.

1216511634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15596321.

The product of its digits is 4320, while the sum is 30.

The square root of 1216511634 is about 34878.5268324223. The cubic root of 1216511634 is about 1067.5103364161.

Adding to 1216511634 its reverse (4361156121), we get a palindrome (5577667755).

The spelling of 1216511634 in words is "one billion, two hundred sixteen million, five hundred eleven thousand, six hundred thirty-four".