1215816489 has 12 divisors (see below), whose sum is σ = 1859484276. Its totient is φ = 762865152.

The previous prime is 1215816463. The next prime is 1215816499. The reversal of 1215816489 is 9846185121.

It is a happy number.

1215816489 is a `hidden beast` number, since 1 + 2 + 1 + 581 + 64 + 8 + 9 = 666.

1215816489 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 464618025 + 751198464 = 21555^2 + 27408^2 .

It is not a de Polignac number, because 1215816489 - 2⁵ = 1215816457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1215816499) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3973104 + ... + 3973409.

It is an arithmetic number, because the mean of its divisors is an integer number (154957023).

Almost surely, 2^1215816489 is an apocalyptic number.

It is an amenable number.

1215816489 is a deficient number, since it is larger than the sum of its proper divisors (643667787).

1215816489 is a wasteful number, since it uses less digits than its factorization.

1215816489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7946536 (or 7946533 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 1215816489 is about 34868.5601796231. The cubic root of 1215816489 is about 1067.3069636894.

The spelling of 1215816489 in words is "one billion, two hundred fifteen million, eight hundred sixteen thousand, four hundred eighty-nine".