21450125 has 16 divisors (see below), whose sum is σ = 26964912. Its totient is φ = 17035200.

The previous prime is 21450119. The next prime is 21450137. The reversal of 21450125 is 52105412.

It can be written as a sum of positive squares in 8 ways, for example, as 2951524 + 18498601 = 1718^2 + 4301^2 .

It is not a de Polignac number, because 21450125 - 2⁶ = 21450061 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21450097 and 21450106.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 19079 + ... + 20171.

It is an arithmetic number, because the mean of its divisors is an integer number (1685307).

Almost surely, 2^21450125 is an apocalyptic number.

21450125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21450125 is a deficient number, since it is larger than the sum of its proper divisors (5514787).

21450125 is a wasteful number, since it uses less digits than its factorization.

21450125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1265 (or 1255 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 21450125 is about 4631.4279655415. The cubic root of 21450125 is about 277.8497065581.

Adding to 21450125 its reverse (52105412), we get a palindrome (73555537).

The spelling of 21450125 in words is "twenty-one million, four hundred fifty thousand, one hundred twenty-five".