21028296 has 32 divisors (see below), whose sum is σ = 52727040. Its totient is φ = 6988608.

The previous prime is 21028291. The next prime is 21028327. The reversal of 21028296 is 69282012.

It is not an unprimeable number, because it can be changed into a prime (21028291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8425 + ... + 10631.

It is an arithmetic number, because the mean of its divisors is an integer number (1647720).

Almost surely, 2^21028296 is an apocalyptic number.

It is an amenable number.

21028296 is an abundant number, since it is smaller than the sum of its proper divisors (31698744).

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

21028296 is a wasteful number, since it uses less digits than its factorization.

21028296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2613 (or 2609 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 21028296 is about 4585.6620023722. The cubic root of 21028296 is about 276.0162771329.

The spelling of 21028296 in words is "twenty-one million, twenty-eight thousand, two hundred ninety-six".