21893568847 has 4 divisors (see below), whose sum is σ = 23181425856. Its totient is φ = 20605711840.

The previous prime is 21893568839. The next prime is 21893568887. The reversal of 21893568847 is 74886539812.

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 21893568847 - 2³ = 21893568839 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 (21893568887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 643928479 + ... + 643928512.

It is an arithmetic number, because the mean of its divisors is an integer number (5795356464).

Almost surely, 2^21893568847 is an apocalyptic number.

21893568847 is a deficient number, since it is larger than the sum of its proper divisors (1287857009).

21893568847 is a wasteful number, since it uses less digits than its factorization.

21893568847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287857008.

The product of its digits is 23224320, while the sum is 61.

It can be divided in two parts, 218935 and 68847, that added together give a palindrome (287782).

The spelling of 21893568847 in words is "twenty-one billion, eight hundred ninety-three million, five hundred sixty-eight thousand, eight hundred forty-seven".