21042325 has 12 divisors (see below), whose sum is σ = 26586468. Its totient is φ = 16515200.

The previous prime is 21042319. The next prime is 21042347. The reversal of 21042325 is 52324012.

It can be written as a sum of positive squares in 6 ways, for example, as 1168561 + 19873764 = 1081^2 + 4458^2 .

It is not a de Polignac number, because 21042325 - 2³ = 21042317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6616 + ... + 9265.

It is an arithmetic number, because the mean of its divisors is an integer number (2215539).

Almost surely, 2^21042325 is an apocalyptic number.

21042325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21042325 is a deficient number, since it is larger than the sum of its proper divisors (5544143).

21042325 is a wasteful number, since it uses less digits than its factorization.

21042325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15944 (or 15939 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21042325 is about 4587.1914065144. The cubic root of 21042325 is about 276.0776447864.

Adding to 21042325 its reverse (52324012), we get a palindrome (73366337).

The spelling of 21042325 in words is "twenty-one million, forty-two thousand, three hundred twenty-five".