1216999158 has 32 divisors (see below), whose sum is σ = 2497583616. Its totient is φ = 395121888.

The previous prime is 1216999127. The next prime is 1216999169. The reversal of 1216999158 is 8519996121.

It is a self number, because there is not a number n which added to its sum of digits gives 1216999158.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88260 + ... + 101112.

It is an arithmetic number, because the mean of its divisors is an integer number (78049488).

Almost surely, 2^1216999158 is an apocalyptic number.

1216999158 is an abundant number, since it is smaller than the sum of its proper divisors (1280584458).

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

1216999158 is a wasteful number, since it uses less digits than its factorization.

1216999158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13268.

The product of its digits is 349920, while the sum is 51.

The square root of 1216999158 is about 34885.5150169809. The cubic root of 1216999158 is about 1067.6529209964.

The spelling of 1216999158 in words is "one billion, two hundred sixteen million, nine hundred ninety-nine thousand, one hundred fifty-eight".