21245952 has 208 divisors, whose sum is σ = 73391360. Its totient is φ = 5308416.

The previous prime is 21245947. The next prime is 21245963. The reversal of 21245952 is 25954212.

It is a tau number, because it is divible by the number of its divisors (208).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1118199 + ... + 1118217.

Almost surely, 2^21245952 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 21245952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36695680).

21245952 is an abundant number, since it is smaller than the sum of its proper divisors (52145408).

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

21245952 is a wasteful number, since it uses less digits than its factorization.

21245952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 44 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 21245952 is about 4609.3331404879. Note that the first 3 decimals coincide. The cubic root of 21245952 is about 276.9653238489.

It can be divided in two parts, 212 and 45952, that added together give a palindrome (46164).

The spelling of 21245952 in words is "twenty-one million, two hundred forty-five thousand, nine hundred fifty-two".