21171382 has 8 divisors (see below), whose sum is σ = 31897656. Its totient is φ = 10538832.

The previous prime is 21171379. The next prime is 21171401. The reversal of 21171382 is 28317112.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 22863 + ... + 23770.

It is an arithmetic number, because the mean of its divisors is an integer number (3987207).

Almost surely, 2^21171382 is an apocalyptic number.

21171382 is a deficient number, since it is larger than the sum of its proper divisors (10726274).

21171382 is a wasteful number, since it uses less digits than its factorization.

21171382 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46862.

The product of its digits is 672, while the sum is 25.

The square root of 21171382 is about 4601.2370075883. The cubic root of 21171382 is about 276.6409088776.

Adding to 21171382 its reverse (28317112), we get a palindrome (49488494).

The spelling of 21171382 in words is "twenty-one million, one hundred seventy-one thousand, three hundred eighty-two".