1216666172 has 12 divisors (see below), whose sum is σ = 2131764936. Its totient is φ = 607590480.

The previous prime is 1216666151. The next prime is 1216666177. The reversal of 1216666172 is 2716666121.

It is a super-3 number, since 3×1216666172³ (a number of 28 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216666177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181958 + ... + 188525.

It is an arithmetic number, because the mean of its divisors is an integer number (177647078).

Almost surely, 2^1216666172 is an apocalyptic number.

It is an amenable number.

1216666172 is a deficient number, since it is larger than the sum of its proper divisors (915098764).

1216666172 is a wasteful number, since it uses less digits than its factorization.

1216666172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371308 (or 371306 counting only the distinct ones).

The product of its digits is 36288, while the sum is 38.

The square root of 1216666172 is about 34880.7421366002. The cubic root of 1216666172 is about 1067.5555377724. Note that the first 4 decimals are identical.

The spelling of 1216666172 in words is "one billion, two hundred sixteen million, six hundred sixty-six thousand, one hundred seventy-two".