21252672 has 168 divisors, whose sum is σ = 72969120. Its totient is φ = 6048000.

The previous prime is 21252653. The next prime is 21252677. The reversal of 21252672 is 27625212.

It is a tau number, because it is divible by the number of its divisors (168).

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 (21252677) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 84547 + ... + 84797.

It is an arithmetic number, because the mean of its divisors is an integer number (434340).

Almost surely, 2^21252672 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 21252672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36484560).

21252672 is an abundant number, since it is smaller than the sum of its proper divisors (51716448).

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

21252672 is a wasteful number, since it uses less digits than its factorization.

21252672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286 (or 263 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21252672 is about 4610.0620386281. The cubic root of 21252672 is about 276.9945217369.

Adding to 21252672 its reverse (27625212), we get a palindrome (48877884).

The spelling of 21252672 in words is "twenty-one million, two hundred fifty-two thousand, six hundred seventy-two".