21186982 has 8 divisors (see below), whose sum is σ = 31815000. Its totient is φ = 10581984.

The previous prime is 21186967. The next prime is 21186983. The reversal of 21186982 is 28968112.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21186983) 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 3 ways as a sum of consecutive naturals, for example, 3232 + ... + 7267.

It is an arithmetic number, because the mean of its divisors is an integer number (3976875).

Almost surely, 2^21186982 is an apocalyptic number.

21186982 is a deficient number, since it is larger than the sum of its proper divisors (10628018).

21186982 is a wasteful number, since it uses less digits than its factorization.

21186982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11510.

The product of its digits is 13824, while the sum is 37.

The square root of 21186982 is about 4602.9318917403. The cubic root of 21186982 is about 276.7088392350.

The spelling of 21186982 in words is "twenty-one million, one hundred eighty-six thousand, nine hundred eighty-two".