21253848 has 192 divisors, whose sum is σ = 70917120. Its totient is φ = 5241600.

The previous prime is 21253763. The next prime is 21253849. The reversal of 21253848 is 84835212.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 400990 + ... + 401042.

It is an arithmetic number, because the mean of its divisors is an integer number (369360).

Almost surely, 2^21253848 is an apocalyptic number.

21253848 is a gapful number since it is divisible by the number (28) 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 21253848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35458560).

21253848 is an abundant number, since it is smaller than the sum of its proper divisors (49663272).

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

21253848 is a wasteful number, since it uses less digits than its factorization.

21253848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 107 counting only the distinct ones).

The product of its digits is 15360, while the sum is 33.

The square root of 21253848 is about 4610.1895839542. The cubic root of 21253848 is about 276.9996307345. Note that the first 3 decimals are identical.

The spelling of 21253848 in words is "twenty-one million, two hundred fifty-three thousand, eight hundred forty-eight".