21530325 has 48 divisors (see below), whose sum is σ = 38836800. Its totient is φ = 10483200.

The previous prime is 21530321. The next prime is 21530329. The reversal of 21530325 is 52303512.

It is an interprime number because it is at equal distance from previous prime (21530321) and next prime (21530329).

It is not a de Polignac number, because 21530325 - 2² = 21530321 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530321) 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 in 47 ways as a sum of consecutive naturals, for example, 41065 + ... + 41585.

It is an arithmetic number, because the mean of its divisors is an integer number (809100).

Almost surely, 2^21530325 is an apocalyptic number.

21530325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21530325 is a deficient number, since it is larger than the sum of its proper divisors (17306475).

21530325 is a wasteful number, since it uses less digits than its factorization.

21530325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 21.

The square root of 21530325 is about 4640.0781243423. The cubic root of 21530325 is about 278.1955605175.

Adding to 21530325 its reverse (52303512), we get a palindrome (73833837).

The spelling of 21530325 in words is "twenty-one million, five hundred thirty thousand, three hundred twenty-five".