1221178089 has 16 divisors (see below), whose sum is σ = 1721065280. Its totient is φ = 768061440.

The previous prime is 1221178003. The next prime is 1221178097. The reversal of 1221178089 is 9808711221.

It is not a de Polignac number, because 1221178089 - 2¹⁹ = 1220653801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221178489) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30712 + ... + 58185.

It is an arithmetic number, because the mean of its divisors is an integer number (107566580).

Almost surely, 2^1221178089 is an apocalyptic number.

1221178089 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1221178089 is a deficient number, since it is larger than the sum of its proper divisors (499887191).

1221178089 is a wasteful number, since it uses less digits than its factorization.

1221178089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89160.

The product of its (nonzero) digits is 16128, while the sum is 39.

The square root of 1221178089 is about 34945.3586188495. The cubic root of 1221178089 is about 1068.8735602433.

The spelling of 1221178089 in words is "one billion, two hundred twenty-one million, one hundred seventy-eight thousand, eighty-nine".