21739253759 has 4 divisors (see below), whose sum is σ = 21756943560. Its totient is φ = 21721563960.

The previous prime is 21739253707. The next prime is 21739253771. The reversal of 21739253759 is 95735293712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21739253759 - 2²⁴ = 21722476543 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 21739253759.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21739243759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8843057 + ... + 8845514.

It is an arithmetic number, because the mean of its divisors is an integer number (5439235890).

Almost surely, 2^21739253759 is an apocalyptic number.

21739253759 is a deficient number, since it is larger than the sum of its proper divisors (17689801).

21739253759 is a wasteful number, since it uses less digits than its factorization.

21739253759 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17689800.

The product of its digits is 3572100, while the sum is 53.

The spelling of 21739253759 in words is "twenty-one billion, seven hundred thirty-nine million, two hundred fifty-three thousand, seven hundred fifty-nine".