21243032425 has 6 divisors (see below), whose sum is σ = 26341360238. Its totient is φ = 16994425920.

The previous prime is 21243032357. The next prime is 21243032453. The reversal of 21243032425 is 52423034212.

It can be written as a sum of positive squares in 3 ways, for example, as 296838441 + 20946193984 = 17229^2 + 144728^2 .

It is not a de Polignac number, because 21243032425 - 2²¹ = 21240935273 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21243032393 and 21243032402.

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, 424860624 + ... + 424860673.

Almost surely, 2^21243032425 is an apocalyptic number.

21243032425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21243032425 is a deficient number, since it is larger than the sum of its proper divisors (5098327813).

21243032425 is an equidigital number, since it uses as much as digits as its factorization.

21243032425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 849721307 (or 849721302 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 21243032425 its reverse (52423034212), we get a palindrome (73666066637).

The spelling of 21243032425 in words is "twenty-one billion, two hundred forty-three million, thirty-two thousand, four hundred twenty-five".