21247323 has 8 divisors (see below), whose sum is σ = 28389888. Its totient is φ = 14134824.

The previous prime is 21247321. The next prime is 21247327. The reversal of 21247323 is 32374212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21247323 - 2¹ = 21247321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21247293 and 21247302.

It is not an unprimeable number, because it can be changed into a prime (21247321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5811 + ... + 8732.

It is an arithmetic number, because the mean of its divisors is an integer number (3548736).

Almost surely, 2^21247323 is an apocalyptic number.

21247323 is a deficient number, since it is larger than the sum of its proper divisors (7142565).

21247323 is a wasteful number, since it uses less digits than its factorization.

21247323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15033.

The product of its digits is 2016, while the sum is 24.

The square root of 21247323 is about 4609.4818580834. The cubic root of 21247323 is about 276.9712812393.

The spelling of 21247323 in words is "twenty-one million, two hundred forty-seven thousand, three hundred twenty-three".