21038472 has 192 divisors, whose sum is σ = 74256000. Its totient is φ = 5256576.

The previous prime is 21038467. The next prime is 21038483. The reversal of 21038472 is 27483012.

21038472 is a `hidden beast` number, since 210 + 384 + 72 = 666.

It is a zygodrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1107279 + ... + 1107297.

It is an arithmetic number, because the mean of its divisors is an integer number (386750).

Almost surely, 2^21038472 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 21038472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37128000).

21038472 is an abundant number, since it is smaller than the sum of its proper divisors (53217528).

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

21038472 is a wasteful number, since it uses less digits than its factorization.

21038472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21038472 is about 4586.7714135326. The cubic root of 21038472 is about 276.0607931617.

The spelling of 21038472 in words is "twenty-one million, thirty-eight thousand, four hundred seventy-two".