21185472 has 112 divisors (see below), whose sum is σ = 69933312. Its totient is φ = 5498880.

The previous prime is 21185459. The next prime is 21185473. The reversal of 21185472 is 27458112.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21185473) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14068 + ... + 15500.

Almost surely, 2^21185472 is an apocalyptic number.

21185472 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21185472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34966656).

21185472 is an abundant number, since it is smaller than the sum of its proper divisors (48747840).

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

21185472 is a wasteful number, since it uses less digits than its factorization.

21185472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1466 (or 1456 counting only the distinct ones).

The product of its digits is 4480, while the sum is 30.

The square root of 21185472 is about 4602.7678629277. The cubic root of 21185472 is about 276.7022653827.

The spelling of 21185472 in words is "twenty-one million, one hundred eighty-five thousand, four hundred seventy-two".