21330620 has 12 divisors (see below), whose sum is σ = 44794344. Its totient is φ = 8532240.

The previous prime is 21330607. The next prime is 21330629. The reversal of 21330620 is 2603312.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533246 + ... + 533285.

It is an arithmetic number, because the mean of its divisors is an integer number (3732862).

Almost surely, 2^21330620 is an apocalyptic number.

21330620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21330620 is an abundant number, since it is smaller than the sum of its proper divisors (23463724).

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

21330620 is a wasteful number, since it uses less digits than its factorization.

21330620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066540 (or 1066538 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 21330620 is about 4618.5084172274. The cubic root of 21330620 is about 277.3327509901.

Adding to 21330620 its reverse (2603312), we get a palindrome (23933932).

The spelling of 21330620 in words is "twenty-one million, three hundred thirty thousand, six hundred twenty".