21198072 has 128 divisors (see below), whose sum is σ = 66240000. Its totient is φ = 5515776.

The previous prime is 21198029. The next prime is 21198083. The reversal of 21198072 is 27089112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92454 + ... + 92682.

It is an arithmetic number, because the mean of its divisors is an integer number (517500).

Almost surely, 2^21198072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21198072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33120000).

21198072 is an abundant number, since it is smaller than the sum of its proper divisors (45041928).

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

21198072 is a wasteful number, since it uses less digits than its factorization.

21198072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 21198072 is about 4604.1364011072. The cubic root of 21198072 is about 276.7571104763.

The spelling of 21198072 in words is "twenty-one million, one hundred ninety-eight thousand, seventy-two".