21124325 has 12 divisors (see below), whose sum is σ = 27098340. Its totient is φ = 16316160.

The previous prime is 21124321. The next prime is 21124339. The reversal of 21124325 is 52342112.

It can be written as a sum of positive squares in 6 ways, for example, as 312481 + 20811844 = 559^2 + 4562^2 .

It is not a de Polignac number, because 21124325 - 2² = 21124321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21124297 and 21124306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124321) by changing a digit.

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, 13844 + ... + 15293.

It is an arithmetic number, because the mean of its divisors is an integer number (2258195).

Almost surely, 2^21124325 is an apocalyptic number.

21124325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21124325 is a deficient number, since it is larger than the sum of its proper divisors (5974015).

21124325 is a wasteful number, since it uses less digits than its factorization.

21124325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29176 (or 29171 counting only the distinct ones).

The product of its digits is 480, while the sum is 20.

The square root of 21124325 is about 4596.1206468064. The cubic root of 21124325 is about 276.4357963346.

Adding to 21124325 its reverse (52342112), we get a palindrome (73466437).

The spelling of 21124325 in words is "twenty-one million, one hundred twenty-four thousand, three hundred twenty-five".