21252025 has 6 divisors (see below), whose sum is σ = 26352542. Its totient is φ = 17001600.

The previous prime is 21252017. The next prime is 21252031. The reversal of 21252025 is 52025212.

It can be written as a sum of positive squares in 3 ways, for example, as 5419584 + 15832441 = 2328^2 + 3979^2 .

It is not a de Polignac number, because 21252025 - 2³ = 21252017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21251993 and 21252011.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425016 + ... + 425065.

Almost surely, 2^21252025 is an apocalyptic number.

21252025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21252025 is a deficient number, since it is larger than the sum of its proper divisors (5100517).

21252025 is an equidigital number, since it uses as much as digits as its factorization.

21252025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850091 (or 850086 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21252025 is about 4609.9918655026. The cubic root of 21252025 is about 276.9917108390.

Adding to 21252025 its reverse (52025212), we get a palindrome (73277237).

The spelling of 21252025 in words is "twenty-one million, two hundred fifty-two thousand, twenty-five".