21251125 has 32 divisors (see below), whose sum is σ = 30700800. Its totient is φ = 14385600.

The previous prime is 21251123. The next prime is 21251129. The reversal of 21251125 is 52115212.

It is not a de Polignac number, because 21251125 - 2¹ = 21251123 is a prime.

It is a super-2 number, since 2×21251125² = 903220627531250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 130294 + ... + 130456.

It is an arithmetic number, because the mean of its divisors is an integer number (959400).

Almost surely, 2^21251125 is an apocalyptic number.

21251125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21251125 is a deficient number, since it is larger than the sum of its proper divisors (9449675).

21251125 is a wasteful number, since it uses less digits than its factorization.

21251125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334 (or 324 counting only the distinct ones).

The product of its digits is 200, while the sum is 19.

The square root of 21251125 is about 4609.8942504140. The cubic root of 21251125 is about 276.9878006852.

Adding to 21251125 its reverse (52115212), we get a palindrome (73366337).

The spelling of 21251125 in words is "twenty-one million, two hundred fifty-one thousand, one hundred twenty-five".