21119728 has 40 divisors (see below), whose sum is σ = 47005920. Its totient is φ = 9004800.

The previous prime is 21119723. The next prime is 21119737. The reversal of 21119728 is 82791112.

It is a self number, because there is not a number n which added to its sum of digits gives 21119728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21119723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29778 + ... + 30478.

It is an arithmetic number, because the mean of its divisors is an integer number (1175148).

Almost surely, 2^21119728 is an apocalyptic number.

21119728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21119728 is an abundant number, since it is smaller than the sum of its proper divisors (25886192).

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

21119728 is a wasteful number, since it uses less digits than its factorization.

21119728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985 (or 979 counting only the distinct ones).

The product of its digits is 2016, while the sum is 31.

The square root of 21119728 is about 4595.6205239336. The cubic root of 21119728 is about 276.4157425570.

The spelling of 21119728 in words is "twenty-one million, one hundred nineteen thousand, seven hundred twenty-eight".