1221856179 has 8 divisors (see below), whose sum is σ = 1634899392. Its totient is φ = 811691880.

The previous prime is 1221856177. The next prime is 1221856187. The reversal of 1221856179 is 9716581221.

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

It is not a de Polignac number, because 1221856179 - 2¹ = 1221856177 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221856179.

It is not an unprimeable number, because it can be changed into a prime (1221856171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 718737 + ... + 720434.

It is an arithmetic number, because the mean of its divisors is an integer number (204362424).

Almost surely, 2^1221856179 is an apocalyptic number.

1221856179 is a deficient number, since it is larger than the sum of its proper divisors (413043213).

1221856179 is a wasteful number, since it uses less digits than its factorization.

1221856179 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439457.

The product of its digits is 60480, while the sum is 42.

The square root of 1221856179 is about 34955.0594192028. The cubic root of 1221856179 is about 1069.0713633231.

The spelling of 1221856179 in words is "one billion, two hundred twenty-one million, eight hundred fifty-six thousand, one hundred seventy-nine".