21768708359 has 4 divisors (see below), whose sum is σ = 21770382816. Its totient is φ = 21767033904.

The previous prime is 21768708347. The next prime is 21768708361. The reversal of 21768708359 is 95380786712.

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 21768708359 - 2⁴ = 21768708343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768708319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 817574 + ... + 843779.

It is an arithmetic number, because the mean of its divisors is an integer number (5442595704).

Almost surely, 2^21768708359 is an apocalyptic number.

21768708359 is a deficient number, since it is larger than the sum of its proper divisors (1674457).

21768708359 is a wasteful number, since it uses less digits than its factorization.

21768708359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1674456.

The product of its (nonzero) digits is 5080320, while the sum is 56.

The spelling of 21768708359 in words is "twenty-one billion, seven hundred sixty-eight million, seven hundred eight thousand, three hundred fifty-nine".