21738219572 has 12 divisors (see below), whose sum is σ = 38177266596. Its totient is φ = 10830429120.

The previous prime is 21738219509. The next prime is 21738219577. The reversal of 21738219572 is 27591283712.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10883496976 + 10854722596 = 104324^2 + 104186^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21738219577) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 9668903 + ... + 9671150.

It is an arithmetic number, because the mean of its divisors is an integer number (3181438883).

Almost surely, 2^21738219572 is an apocalyptic number.

It is an amenable number.

21738219572 is a deficient number, since it is larger than the sum of its proper divisors (16439047024).

21738219572 is a wasteful number, since it uses less digits than its factorization.

21738219572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19340338 (or 19340336 counting only the distinct ones).

The product of its digits is 423360, while the sum is 47.

The spelling of 21738219572 in words is "twenty-one billion, seven hundred thirty-eight million, two hundred nineteen thousand, five hundred seventy-two".