21984125 has 8 divisors (see below), whose sum is σ = 27436344. Its totient is φ = 17587200.

The previous prime is 21984119. The next prime is 21984133. The reversal of 21984125 is 52148912.

It can be written as a sum of positive squares in 4 ways, for example, as 63001 + 21921124 = 251^2 + 4682^2 .

It is not a de Polignac number, because 21984125 - 2⁸ = 21983869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21984091 and 21984100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87812 + ... + 88061.

It is an arithmetic number, because the mean of its divisors is an integer number (3429543).

Almost surely, 2^21984125 is an apocalyptic number.

21984125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21984125 is a deficient number, since it is larger than the sum of its proper divisors (5452219).

21984125 is an equidigital number, since it uses as much as digits as its factorization.

21984125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175888 (or 175878 counting only the distinct ones).

The product of its digits is 5760, while the sum is 32.

The square root of 21984125 is about 4688.7231737436. The cubic root of 21984125 is about 280.1365193110.

The spelling of 21984125 in words is "twenty-one million, nine hundred eighty-four thousand, one hundred twenty-five".