21717218194 has 32 divisors (see below), whose sum is σ = 38986603776. Its totient is φ = 8870991360.

The previous prime is 21717218189. The next prime is 21717218203. The reversal of 21717218194 is 49181271712.

It is a self number, because there is not a number n which added to its sum of digits gives 21717218194.

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, 29527 + ... + 210490.

It is an arithmetic number, because the mean of its divisors is an integer number (1218331368).

Almost surely, 2^21717218194 is an apocalyptic number.

21717218194 is a deficient number, since it is larger than the sum of its proper divisors (17269385582).

21717218194 is a wasteful number, since it uses less digits than its factorization.

21717218194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240330.

The product of its digits is 56448, while the sum is 43.

The spelling of 21717218194 in words is "twenty-one billion, seven hundred seventeen million, two hundred eighteen thousand, one hundred ninety-four".