21095825 has 6 divisors (see below), whose sum is σ = 26158854. Its totient is φ = 16876640.

The previous prime is 21095783. The next prime is 21095839. The reversal of 21095825 is 52859012.

It can be written as a sum of positive squares in 3 ways, for example, as 456976 + 20638849 = 676^2 + 4543^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21095825 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21095791 and 21095800.

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 5 ways as a sum of consecutive naturals, for example, 421892 + ... + 421941.

It is an arithmetic number, because the mean of its divisors is an integer number (4359809).

Almost surely, 2^21095825 is an apocalyptic number.

21095825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21095825 is a deficient number, since it is larger than the sum of its proper divisors (5063029).

21095825 is an equidigital number, since it uses as much as digits as its factorization.

21095825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843843 (or 843838 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 21095825 is about 4593.0191595507. The cubic root of 21095825 is about 276.3114220895.

The spelling of 21095825 in words is "twenty-one million, ninety-five thousand, eight hundred twenty-five".