21432425 has 12 divisors (see below), whose sum is σ = 30373056. Its totient is φ = 14696400.

The previous prime is 21432413. The next prime is 21432443. The reversal of 21432425 is 52423412.

It is a happy number.

It is not a de Polignac number, because 21432425 - 2⁴ = 21432409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21432425.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61061 + ... + 61410.

It is an arithmetic number, because the mean of its divisors is an integer number (2531088).

Almost surely, 2^21432425 is an apocalyptic number.

21432425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21432425 is a deficient number, since it is larger than the sum of its proper divisors (8940631).

21432425 is a wasteful number, since it uses less digits than its factorization.

21432425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122488 (or 122483 counting only the distinct ones).

The product of its digits is 1920, while the sum is 23.

The square root of 21432425 is about 4629.5167134378. The cubic root of 21432425 is about 277.7732611117.

Adding to 21432425 its reverse (52423412), we get a palindrome (73855837).

The spelling of 21432425 in words is "twenty-one million, four hundred thirty-two thousand, four hundred twenty-five".