21385856884 has 48 divisors (see below), whose sum is σ = 43959202560. Its totient is φ = 8911261440.

The previous prime is 21385856873. The next prime is 21385856953. The reversal of 21385856884 is 48865858312.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1608504 + ... + 1621744.

It is an arithmetic number, because the mean of its divisors is an integer number (915816720).

Almost surely, 2^21385856884 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21385856884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21979601280).

21385856884 is an abundant number, since it is smaller than the sum of its proper divisors (22573345676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21385856884 is a wasteful number, since it uses less digits than its factorization.

21385856884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14848 (or 14846 counting only the distinct ones).

The product of its digits is 14745600, while the sum is 58.

The spelling of 21385856884 in words is "twenty-one billion, three hundred eighty-five million, eight hundred fifty-six thousand, eight hundred eighty-four".