21135248 has 20 divisors (see below), whose sum is σ = 41128320. Its totient is φ = 10521504.

The previous prime is 21135227. The next prime is 21135259. The reversal of 21135248 is 84253112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1061 + ... + 6587.

It is an arithmetic number, because the mean of its divisors is an integer number (2056416).

Almost surely, 2^21135248 is an apocalyptic number.

It is an amenable number.

21135248 is a deficient number, since it is larger than the sum of its proper divisors (19993072).

21135248 is a wasteful number, since it uses less digits than its factorization.

21135248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5774 (or 5768 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 21135248 is about 4597.3087779700. The cubic root of 21135248 is about 276.4834347469.

The spelling of 21135248 in words is "twenty-one million, one hundred thirty-five thousand, two hundred forty-eight".