1216894544 has 20 divisors (see below), whose sum is σ = 2496423924. Its totient is φ = 572656128.

The previous prime is 1216894541. The next prime is 1216894559. The reversal of 1216894544 is 4454986121.

It can be written as a sum of positive squares in 2 ways, for example, as 841000000 + 375894544 = 29000^2 + 19388^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1216894495 and 1216894504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216894541) 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, 2236667 + ... + 2237210.

Almost surely, 2^1216894544 is an apocalyptic number.

It is an amenable number.

1216894544 is an abundant number, since it is smaller than the sum of its proper divisors (1279529380).

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

1216894544 is a wasteful number, since it uses less digits than its factorization.

1216894544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4473902 (or 4473896 counting only the distinct ones).

The product of its digits is 276480, while the sum is 44.

The square root of 1216894544 is about 34884.0155945384. The cubic root of 1216894544 is about 1067.6223280847.

The spelling of 1216894544 in words is "one billion, two hundred sixteen million, eight hundred ninety-four thousand, five hundred forty-four".