21025936 has 20 divisors (see below), whose sum is σ = 42052864. Its totient is φ = 10173600.

The previous prime is 21025909. The next prime is 21025937. The reversal of 21025936 is 63952012.

21025936 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21025937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20700 + ... + 21691.

Almost surely, 2^21025936 is an apocalyptic number.

It is an amenable number.

21025936 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21025936 is a wasteful number, since it uses less digits than its factorization.

21025936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42430 (or 42424 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21025936 is about 4585.4046713458. The cubic root of 21025936 is about 276.0059510024.

Adding to 21025936 its reverse (63952012), we get a palindrome (84977948).

The spelling of 21025936 in words is "twenty-one million, twenty-five thousand, nine hundred thirty-six".