21428196 has 12 divisors (see below), whose sum is σ = 49999152. Its totient is φ = 7142728.

The previous prime is 21428191. The next prime is 21428207. The reversal of 21428196 is 69182412.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21428191) 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, 892830 + ... + 892853.

It is an arithmetic number, because the mean of its divisors is an integer number (4166596).

Almost surely, 2^21428196 is an apocalyptic number.

It is an amenable number.

21428196 is an abundant number, since it is smaller than the sum of its proper divisors (28570956).

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

21428196 is a wasteful number, since it uses less digits than its factorization.

21428196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785690 (or 1785688 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

The square root of 21428196 is about 4629.0599477648. The cubic root of 21428196 is about 277.7549900358.

The spelling of 21428196 in words is "twenty-one million, four hundred twenty-eight thousand, one hundred ninety-six".