21843125 has 10 divisors (see below), whose sum is σ = 27295950. Its totient is φ = 17474000.

The previous prime is 21843121. The next prime is 21843131. The reversal of 21843125 is 52134812.

It can be written as a sum of positive squares in 5 ways, for example, as 14799409 + 7043716 = 3847^2 + 2654^2 .

It is not a de Polignac number, because 21843125 - 2² = 21843121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21843094 and 21843103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21843121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 16850 + ... + 18099.

It is an arithmetic number, because the mean of its divisors is an integer number (2729595).

Almost surely, 2^21843125 is an apocalyptic number.

21843125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21843125 is a deficient number, since it is larger than the sum of its proper divisors (5452825).

21843125 is an frugal number, since it uses more digits than its factorization.

21843125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34969 (or 34954 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 21843125 is about 4673.6629103948. The cubic root of 21843125 is about 279.5363286870.

Adding to 21843125 its reverse (52134812), we get a palindrome (73977937).

The spelling of 21843125 in words is "twenty-one million, eight hundred forty-three thousand, one hundred twenty-five".