21152125 has 8 divisors (see below), whose sum is σ = 26398008. Its totient is φ = 16921600.

The previous prime is 21152099. The next prime is 21152143. The reversal of 21152125 is 52125112.

It can be written as a sum of positive squares in 4 ways, for example, as 111556 + 21040569 = 334^2 + 4587^2 .

It is not a de Polignac number, because 21152125 - 2⁵ = 21152093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84484 + ... + 84733.

It is an arithmetic number, because the mean of its divisors is an integer number (3299751).

Almost surely, 2^21152125 is an apocalyptic number.

21152125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21152125 is a deficient number, since it is larger than the sum of its proper divisors (5245883).

21152125 is an equidigital number, since it uses as much as digits as its factorization.

21152125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169232 (or 169222 counting only the distinct ones).

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

The square root of 21152125 is about 4599.1439420831. The cubic root of 21152125 is about 276.5570080410.

Adding to 21152125 its reverse (52125112), we get a palindrome (73277237).

The spelling of 21152125 in words is "twenty-one million, one hundred fifty-two thousand, one hundred twenty-five".