21330425 has 6 divisors (see below), whose sum is σ = 26449758. Its totient is φ = 17064320.

The previous prime is 21330403. The next prime is 21330443. The reversal of 21330425 is 52403312.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 5161984 + 16168441 = 2272^2 + 4021^2 .

It is not a de Polignac number, because 21330425 - 2¹⁰ = 21329401 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21330397 and 21330406.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 426584 + ... + 426633.

It is an arithmetic number, because the mean of its divisors is an integer number (4408293).

Almost surely, 2^21330425 is an apocalyptic number.

21330425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21330425 is a deficient number, since it is larger than the sum of its proper divisors (5119333).

21330425 is an equidigital number, since it uses as much as digits as its factorization.

21330425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853227 (or 853222 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 21330425 is about 4618.4873064673. The cubic root of 21330425 is about 277.3319058818.

Adding to 21330425 its reverse (52403312), we get a palindrome (73733737).

The spelling of 21330425 in words is "twenty-one million, three hundred thirty thousand, four hundred twenty-five".