21172248 has 24 divisors (see below), whose sum is σ = 57341700. Its totient is φ = 7057392.

The previous prime is 21172243. The next prime is 21172253. The reversal of 21172248 is 84227112.

It is an interprime number because it is at equal distance from previous prime (21172243) and next prime (21172253).

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21172241) 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 5 ways as a sum of consecutive naturals, for example, 146958 + ... + 147101.

Almost surely, 2^21172248 is an apocalyptic number.

It is an amenable number.

21172248 is an abundant number, since it is smaller than the sum of its proper divisors (36169452).

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

21172248 is a wasteful number, since it uses less digits than its factorization.

21172248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294071 (or 294064 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 21172248 is about 4601.3311117545. The cubic root of 21172248 is about 276.6446807580.

The spelling of 21172248 in words is "twenty-one million, one hundred seventy-two thousand, two hundred forty-eight".