21721111194 has 32 divisors (see below), whose sum is σ = 44401950720. Its totient is φ = 7080661872.

The previous prime is 21721111187. The next prime is 21721111267. The reversal of 21721111194 is 49111112712.

It is a super-2 number, since 2×21721111194² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 330567 + ... + 390789.

It is an arithmetic number, because the mean of its divisors is an integer number (1387560960).

Almost surely, 2^21721111194 is an apocalyptic number.

21721111194 is an abundant number, since it is smaller than the sum of its proper divisors (22680839526).

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

21721111194 is a wasteful number, since it uses less digits than its factorization.

21721111194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61554.

The product of its digits is 1008, while the sum is 30.

The spelling of 21721111194 in words is "twenty-one billion, seven hundred twenty-one million, one hundred eleven thousand, one hundred ninety-four".