21250125 has 48 divisors (see below), whose sum is σ = 41281968. Its totient is φ = 10454400.

The previous prime is 21250123. The next prime is 21250129. The reversal of 21250125 is 52105212.

It can be written as a sum of positive squares in 8 ways, for example, as 4652649 + 16597476 = 2157^2 + 4074^2 .

It is not a de Polignac number, because 21250125 - 2¹ = 21250123 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 21250098 and 21250107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13899 + ... + 15351.

It is an arithmetic number, because the mean of its divisors is an integer number (860041).

Almost surely, 2^21250125 is an apocalyptic number.

21250125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21250125 is a deficient number, since it is larger than the sum of its proper divisors (20031843).

21250125 is a wasteful number, since it uses less digits than its factorization.

21250125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1487 (or 1474 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 21250125 is about 4609.7857867801. The cubic root of 21250125 is about 276.9834559404.

Adding to 21250125 its reverse (52105212), we get a palindrome (73355337).

The spelling of 21250125 in words is "twenty-one million, two hundred fifty thousand, one hundred twenty-five".