21132425 has 24 divisors (see below), whose sum is σ = 27420120. Its totient is φ = 16140800.

The previous prime is 21132383. The next prime is 21132481. The reversal of 21132425 is 52423112.

It can be written as a sum of positive squares in 12 ways, for example, as 11744329 + 9388096 = 3427^2 + 3064^2 .

It is not a de Polignac number, because 21132425 - 2²⁰ = 20083849 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21132397 and 21132406.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54131 + ... + 54519.

It is an arithmetic number, because the mean of its divisors is an integer number (1142505).

Almost surely, 2^21132425 is an apocalyptic number.

21132425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21132425 is a deficient number, since it is larger than the sum of its proper divisors (6287695).

21132425 is a wasteful number, since it uses less digits than its factorization.

21132425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 488 counting only the distinct ones).

The product of its digits is 480, while the sum is 20.

The square root of 21132425 is about 4597.0017402651. The cubic root of 21132425 is about 276.4711243876.

Adding to 21132425 its reverse (52423112), we get a palindrome (73555537).

The spelling of 21132425 in words is "twenty-one million, one hundred thirty-two thousand, four hundred twenty-five".