21825072 has 80 divisors (see below), whose sum is σ = 65968000. Its totient is φ = 6889536.

The previous prime is 21825071. The next prime is 21825109. The reversal of 21825072 is 27052812.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21825071) 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, 6879 + ... + 9537.

It is an arithmetic number, because the mean of its divisors is an integer number (824600).

Almost surely, 2^21825072 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 21825072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32984000).

21825072 is an abundant number, since it is smaller than the sum of its proper divisors (44142928).

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

21825072 is a wasteful number, since it uses less digits than its factorization.

21825072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2695 (or 2683 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 21825072 is about 4671.7311566485. The cubic root of 21825072 is about 279.4592966650.

Adding to 21825072 its reverse (27052812), we get a palindrome (48877884).

The spelling of 21825072 in words is "twenty-one million, eight hundred twenty-five thousand, seventy-two".