21143425 has 12 divisors (see below), whose sum is σ = 26288496. Its totient is φ = 16869200.

The previous prime is 21143411. The next prime is 21143453. The reversal of 21143425 is 52434112.

It is not a de Polignac number, because 21143425 - 2²³ = 12754817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21143396 and 21143405.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 10770 + ... + 12580.

It is an arithmetic number, because the mean of its divisors is an integer number (2190708).

Almost surely, 2^21143425 is an apocalyptic number.

21143425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21143425 is a deficient number, since it is larger than the sum of its proper divisors (5145071).

21143425 is a wasteful number, since it uses less digits than its factorization.

21143425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2288 (or 2283 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21143425 is about 4598.1980166148. The cubic root of 21143425 is about 276.5190863047.

Adding to 21143425 its reverse (52434112), we get a palindrome (73577537).

The spelling of 21143425 in words is "twenty-one million, one hundred forty-three thousand, four hundred twenty-five".