21382447 has 8 divisors (see below), whose sum is σ = 22979376. Its totient is φ = 19823232.

The previous prime is 21382441. The next prime is 21382453. The reversal of 21382447 is 74428312.

It is an interprime number because it is at equal distance from previous prime (21382441) and next prime (21382453).

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 21382447 - 2¹¹ = 21380399 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21382441) 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, 8248 + ... + 10525.

It is an arithmetic number, because the mean of its divisors is an integer number (2872422).

Almost surely, 2^21382447 is an apocalyptic number.

21382447 is a deficient number, since it is larger than the sum of its proper divisors (1596929).

21382447 is a wasteful number, since it uses less digits than its factorization.

21382447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18857.

The product of its digits is 10752, while the sum is 31.

The square root of 21382447 is about 4624.1158073733. The cubic root of 21382447 is about 277.5571810851.

The spelling of 21382447 in words is "twenty-one million, three hundred eighty-two thousand, four hundred forty-seven".