21191919184 has 10 divisors (see below), whose sum is σ = 41059343450. Its totient is φ = 10595959584.

The previous prime is 21191919181. The next prime is 21191919187. The reversal of 21191919184 is 48191919112.

It is an interprime number because it is at equal distance from previous prime (21191919181) and next prime (21191919187).

It can be written as a sum of positive squares in only one way, i.e., 17535056400 + 3656862784 = 132420^2 + 60472^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21191919181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 662247459 + ... + 662247490.

It is an arithmetic number, because the mean of its divisors is an integer number (4105934345).

Almost surely, 2^21191919184 is an apocalyptic number.

It is an amenable number.

21191919184 is a deficient number, since it is larger than the sum of its proper divisors (19867424266).

21191919184 is a wasteful number, since it uses less digits than its factorization.

21191919184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1324494957 (or 1324494951 counting only the distinct ones).

The product of its digits is 46656, while the sum is 46.

The spelling of 21191919184 in words is "twenty-one billion, one hundred ninety-one million, nine hundred nineteen thousand, one hundred eighty-four".