21321884 has 6 divisors (see below), whose sum is σ = 37313304. Its totient is φ = 10660940.

The previous prime is 21321869. The next prime is 21321887. The reversal of 21321884 is 48812312.

It is a plaindrome in base 13 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321887) 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 as a sum of consecutive naturals, namely, 2665232 + ... + 2665239.

It is an arithmetic number, because the mean of its divisors is an integer number (6218884).

Almost surely, 2^21321884 is an apocalyptic number.

It is an amenable number.

21321884 is a deficient number, since it is larger than the sum of its proper divisors (15991420).

21321884 is a wasteful number, since it uses less digits than its factorization.

21321884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5330475 (or 5330473 counting only the distinct ones).

The product of its digits is 3072, while the sum is 29.

The square root of 21321884 is about 4617.5625604858. The cubic root of 21321884 is about 277.2948850844.

The spelling of 21321884 in words is "twenty-one million, three hundred twenty-one thousand, eight hundred eighty-four".