21079428 has 24 divisors (see below), whose sum is σ = 49648032. Its totient is φ = 6960384.

The previous prime is 21079393. The next prime is 21079459. The reversal of 21079428 is 82497012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6925 + ... + 9492.

It is an arithmetic number, because the mean of its divisors is an integer number (2068668).

Almost surely, 2^21079428 is an apocalyptic number.

It is an amenable number.

21079428 is an abundant number, since it is smaller than the sum of its proper divisors (28568604).

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

21079428 is a wasteful number, since it uses less digits than its factorization.

21079428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16531 (or 16529 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21079428 is about 4591.2338210986. The cubic root of 21079428 is about 276.2398146706.

The spelling of 21079428 in words is "twenty-one million, seventy-nine thousand, four hundred twenty-eight".