21384547 has 8 divisors (see below), whose sum is σ = 21802176. Its totient is φ = 20970432.

The previous prime is 21384533. The next prime is 21384613. The reversal of 21384547 is 74548312.

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

It is a cyclic number.

It is not a de Polignac number, because 21384547 - 2¹¹ = 21382499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21384347) 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, 13638 + ... + 15124.

It is an arithmetic number, because the mean of its divisors is an integer number (2725272).

Almost surely, 2^21384547 is an apocalyptic number.

21384547 is a deficient number, since it is larger than the sum of its proper divisors (417629).

21384547 is a wasteful number, since it uses less digits than its factorization.

21384547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757.

The product of its digits is 26880, while the sum is 34.

The square root of 21384547 is about 4624.3428722360. The cubic root of 21384547 is about 277.5662672139.

The spelling of 21384547 in words is "twenty-one million, three hundred eighty-four thousand, five hundred forty-seven".