1216732985 has 8 divisors (see below), whose sum is σ = 1572393480. Its totient is φ = 898510464.

The previous prime is 1216732969. The next prime is 1216732991. The reversal of 1216732985 is 5892376121.

It can be written as a sum of positive squares in 4 ways, for example, as 59644729 + 1157088256 = 7723^2 + 34016^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1216732985 - 2⁴ = 1216732969 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9359420 + ... + 9359549.

It is an arithmetic number, because the mean of its divisors is an integer number (196549185).

Almost surely, 2^1216732985 is an apocalyptic number.

It is an amenable number.

1216732985 is a deficient number, since it is larger than the sum of its proper divisors (355660495).

1216732985 is a wasteful number, since it uses less digits than its factorization.

1216732985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18718987.

The product of its digits is 181440, while the sum is 44.

The square root of 1216732985 is about 34881.6998582351. The cubic root of 1216732985 is about 1067.5750789536.

The spelling of 1216732985 in words is "one billion, two hundred sixteen million, seven hundred thirty-two thousand, nine hundred eighty-five".