21101248 has 112 divisors (see below), whose sum is σ = 52506880. Its totient is φ = 8211456.

The previous prime is 21101243. The next prime is 21101251. The reversal of 21101248 is 84210112.

It is a happy number.

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

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (21101243) 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 15 ways as a sum of consecutive naturals, for example, 314911 + ... + 314977.

Almost surely, 2^21101248 is an apocalyptic number.

21101248 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 21101248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26253440).

21101248 is an abundant number, since it is smaller than the sum of its proper divisors (31405632).

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

21101248 is a wasteful number, since it uses less digits than its factorization.

21101248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 21101248 is about 4593.6094740411. The cubic root of 21101248 is about 276.3350967339.

The spelling of 21101248 in words is "twenty-one million, one hundred one thousand, two hundred forty-eight".