21248370 has 144 divisors (see below), whose sum is σ = 65774592. Its totient is φ = 4717440.

The previous prime is 21248369. The next prime is 21248401. The reversal of 21248370 is 7384212.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 167247 + ... + 167373.

It is an arithmetic number, because the mean of its divisors is an integer number (456768).

Almost surely, 2^21248370 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21248370, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32887296).

21248370 is an abundant number, since it is smaller than the sum of its proper divisors (44526222).

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

21248370 is a wasteful number, since it uses less digits than its factorization.

21248370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21248370 is about 4609.5954269328. The cubic root of 21248370 is about 276.9758305837.

The spelling of 21248370 in words is "twenty-one million, two hundred forty-eight thousand, three hundred seventy".