1216055986 has 8 divisors (see below), whose sum is σ = 1873383660. Its totient is φ = 591594768.

The previous prime is 1216055983. The next prime is 1216055987. The reversal of 1216055986 is 6895506121.

It can be written as a sum of positive squares in 2 ways, for example, as 916938961 + 299117025 = 30281^2 + 17295^2 .

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

It is a super-2 number, since 2×1216055986² = 2957584322172864392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216055983) 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, 8216521 + ... + 8216668.

Almost surely, 2^1216055986 is an apocalyptic number.

1216055986 is a deficient number, since it is larger than the sum of its proper divisors (657327674).

1216055986 is a wasteful number, since it uses less digits than its factorization.

1216055986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16433228.

The product of its (nonzero) digits is 129600, while the sum is 43.

The square root of 1216055986 is about 34871.9942934155. The cubic root of 1216055986 is about 1067.3770400636.

The spelling of 1216055986 in words is "one billion, two hundred sixteen million, fifty-five thousand, nine hundred eighty-six".