21043425 has 48 divisors (see below), whose sum is σ = 37997568. Its totient is φ = 10214400.

The previous prime is 21043423. The next prime is 21043441. The reversal of 21043425 is 52434012.

It is not a de Polignac number, because 21043425 - 2¹ = 21043423 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21043423) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 110080 + ... + 110270.

It is an arithmetic number, because the mean of its divisors is an integer number (791616).

Almost surely, 2^21043425 is an apocalyptic number.

21043425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21043425 is a deficient number, since it is larger than the sum of its proper divisors (16954143).

21043425 is a wasteful number, since it uses less digits than its factorization.

21043425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21043425 is about 4587.3113040211. The cubic root of 21043425 is about 276.0824554101.

Adding to 21043425 its reverse (52434012), we get a palindrome (73477437).

The spelling of 21043425 in words is "twenty-one million, forty-three thousand, four hundred twenty-five".