1216161204 has 24 divisors (see below), whose sum is σ = 2838554208. Its totient is φ = 405266400.

The previous prime is 1216161203. The next prime is 1216161211. The reversal of 1216161204 is 4021616121.

It is a happy number.

It is a super-2 number, since 2×1216161204² = 2958096148229459232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216161203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33054 + ... + 59370.

It is an arithmetic number, because the mean of its divisors is an integer number (118273092).

Almost surely, 2^1216161204 is an apocalyptic number.

It is an amenable number.

1216161204 is an abundant number, since it is smaller than the sum of its proper divisors (1622393004).

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

1216161204 is a wasteful number, since it uses less digits than its factorization.

1216161204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30175 (or 30173 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 1216161204 is about 34873.5028925974. The cubic root of 1216161204 is about 1067.4078237445.

Adding to 1216161204 its reverse (4021616121), we get a palindrome (5237777325).

The spelling of 1216161204 in words is "one billion, two hundred sixteen million, one hundred sixty-one thousand, two hundred four".