21854518 has 8 divisors (see below), whose sum is σ = 37464912. Its totient is φ = 9366216.

The previous prime is 21854507. The next prime is 21854527. The reversal of 21854518 is 81545812.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780505 + ... + 780532.

It is an arithmetic number, because the mean of its divisors is an integer number (4683114).

Almost surely, 2^21854518 is an apocalyptic number.

21854518 is a deficient number, since it is larger than the sum of its proper divisors (15610394).

21854518 is a wasteful number, since it uses less digits than its factorization.

21854518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561046.

The product of its digits is 12800, while the sum is 34.

The square root of 21854518 is about 4674.8816027788. The cubic root of 21854518 is about 279.5849206939.

The spelling of 21854518 in words is "twenty-one million, eight hundred fifty-four thousand, five hundred eighteen".