21712724338 has 8 divisors (see below), whose sum is σ = 32611222188. Its totient is φ = 10842316944.

The previous prime is 21712724333. The next prime is 21712724351. The reversal of 21712724338 is 83342721712.

21712724338 is nontrivially palindromic in base 5.

It can be written as a sum of positive squares in 2 ways, for example, as 21312204169 + 400520169 = 145987^2 + 20013^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21712724338.

It is not an unprimeable number, because it can be changed into a prime (21712724333) 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, 7020681 + ... + 7023772.

Almost surely, 2^21712724338 is an apocalyptic number.

21712724338 is a deficient number, since it is larger than the sum of its proper divisors (10898497850).

21712724338 is a wasteful number, since it uses less digits than its factorization.

21712724338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14045228.

The product of its digits is 112896, while the sum is 40.

The spelling of 21712724338 in words is "twenty-one billion, seven hundred twelve million, seven hundred twenty-four thousand, three hundred thirty-eight".