21247324 has 24 divisors (see below), whose sum is σ = 43645280. Its totient is φ = 8859456.

The previous prime is 21247321. The next prime is 21247327. The reversal of 21247324 is 42374212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21247321) and next prime (21247327).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21247321) 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 7 ways as a sum of consecutive naturals, for example, 9219 + ... + 11290.

Almost surely, 2^21247324 is an apocalyptic number.

It is an amenable number.

21247324 is an abundant number, since it is smaller than the sum of its proper divisors (22397956).

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

21247324 is a wasteful number, since it uses less digits than its factorization.

21247324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20557 (or 20555 counting only the distinct ones).

The product of its digits is 2688, while the sum is 25.

The square root of 21247324 is about 4609.4819665555. The cubic root of 21247324 is about 276.9712855845.

The spelling of 21247324 in words is "twenty-one million, two hundred forty-seven thousand, three hundred twenty-four".