21300064 has 48 divisors (see below), whose sum is σ = 45042480. Its totient is φ = 9884160.

The previous prime is 21300061. The next prime is 21300077. The reversal of 21300064 is 46000312.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31894 + ... + 32554.

It is an arithmetic number, because the mean of its divisors is an integer number (938385).

Almost surely, 2^21300064 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 21300064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22521240).

21300064 is an abundant number, since it is smaller than the sum of its proper divisors (23742416).

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

21300064 is a wasteful number, since it uses less digits than its factorization.

21300064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743 (or 735 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21300064 is about 4615.1992373028. The cubic root of 21300064 is about 277.2002618084.

Adding to 21300064 its reverse (46000312), we get a palindrome (67300376).

The spelling of 21300064 in words is "twenty-one million, three hundred thousand, sixty-four".