1221166672 has 20 divisors (see below), whose sum is σ = 2581102656. Its totient is φ = 555075680.

The previous prime is 1221166631. The next prime is 1221166699. The reversal of 1221166672 is 2766611221.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3469048 + ... + 3469399.

Almost surely, 2^1221166672 is an apocalyptic number.

It is an amenable number.

1221166672 is an abundant number, since it is smaller than the sum of its proper divisors (1359935984).

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

1221166672 is a wasteful number, since it uses less digits than its factorization.

1221166672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6938466 (or 6938460 counting only the distinct ones).

The product of its digits is 12096, while the sum is 34.

The square root of 1221166672 is about 34945.1952634407. The cubic root of 1221166672 is about 1068.8702292065.

Adding to 1221166672 its reverse (2766611221), we get a palindrome (3987777893).

The spelling of 1221166672 in words is "one billion, two hundred twenty-one million, one hundred sixty-six thousand, six hundred seventy-two".