21838721713 has 8 divisors (see below), whose sum is σ = 23224331880. Its totient is φ = 20464331520.

The previous prime is 21838721711. The next prime is 21838721741. The reversal of 21838721713 is 31712783812.

It can be written as a sum of positive squares in 4 ways, for example, as 9839052864 + 11999668849 = 99192^2 + 109543^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21838721713 - 2¹ = 21838721711 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21838721713.

It is not an unprimeable number, because it can be changed into a prime (21838721711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2800978 + ... + 2808763.

It is an arithmetic number, because the mean of its divisors is an integer number (2903041485).

Almost surely, 2^21838721713 is an apocalyptic number.

It is an amenable number.

21838721713 is a deficient number, since it is larger than the sum of its proper divisors (1385610167).

21838721713 is a wasteful number, since it uses less digits than its factorization.

21838721713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5609987.

The product of its digits is 112896, while the sum is 43.

It can be divided in two parts, 218387 and 21713, that added together give a square (240100 = 490²).

The spelling of 21838721713 in words is "twenty-one billion, eight hundred thirty-eight million, seven hundred twenty-one thousand, seven hundred thirteen".