21382018 has 8 divisors (see below), whose sum is σ = 36654912. Its totient is φ = 9163716.

The previous prime is 21382007. The next prime is 21382021. The reversal of 21382018 is 81028312.

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

It is a junction number, because it is equal to n+sod(n) for n = 21381983 and 21382001.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 763630 + ... + 763657.

It is an arithmetic number, because the mean of its divisors is an integer number (4581864).

Almost surely, 2^21382018 is an apocalyptic number.

21382018 is a deficient number, since it is larger than the sum of its proper divisors (15272894).

21382018 is a wasteful number, since it uses less digits than its factorization.

21382018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1527296.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 21382018 is about 4624.0694198941. The cubic root of 21382018 is about 277.5553248456. Note that the first 3 decimals are identical.

The spelling of 21382018 in words is "twenty-one million, three hundred eighty-two thousand, eighteen".