1216144564 has 12 divisors (see below), whose sum is σ = 2185773604. Its totient is φ = 591637824.

The previous prime is 1216144561. The next prime is 1216144591. The reversal of 1216144564 is 4654416121.

It can be written as a sum of positive squares in 2 ways, for example, as 488763664 + 727380900 = 22108^2 + 26970^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216144561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4108449 + ... + 4108744.

Almost surely, 2^1216144564 is an apocalyptic number.

It is an amenable number.

1216144564 is a deficient number, since it is larger than the sum of its proper divisors (969629040).

1216144564 is a wasteful number, since it uses less digits than its factorization.

1216144564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8217234 (or 8217232 counting only the distinct ones).

The product of its digits is 23040, while the sum is 34.

The square root of 1216144564 is about 34873.2643152315. The cubic root of 1216144564 is about 1067.4029554899.

The spelling of 1216144564 in words is "one billion, two hundred sixteen million, one hundred forty-four thousand, five hundred sixty-four".