21085325 has 12 divisors (see below), whose sum is σ = 26212980. Its totient is φ = 16824960.

The previous prime is 21085289. The next prime is 21085343. The reversal of 21085325 is 52358012.

It can be written as a sum of positive squares in 6 ways, for example, as 90601 + 20994724 = 301^2 + 4582^2 .

It is not a de Polignac number, because 21085325 - 2⁶ = 21085261 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21085294 and 21085303.

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, 11897 + ... + 13553.

It is an arithmetic number, because the mean of its divisors is an integer number (2184415).

Almost surely, 2^21085325 is an apocalyptic number.

21085325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21085325 is a deficient number, since it is larger than the sum of its proper divisors (5127655).

21085325 is a wasteful number, since it uses less digits than its factorization.

21085325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2176 (or 2171 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 21085325 is about 4591.8759782904. The cubic root of 21085325 is about 276.2655717627.

The spelling of 21085325 in words is "twenty-one million, eighty-five thousand, three hundred twenty-five".