21618814 has 8 divisors (see below), whose sum is σ = 37060848. Its totient is φ = 9265200.

The previous prime is 21618803. The next prime is 21618847. The reversal of 21618814 is 41881612.

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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 772087 + ... + 772114.

It is an arithmetic number, because the mean of its divisors is an integer number (4632606).

Almost surely, 2^21618814 is an apocalyptic number.

21618814 is a deficient number, since it is larger than the sum of its proper divisors (15442034).

21618814 is a wasteful number, since it uses less digits than its factorization.

21618814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544210.

The product of its digits is 3072, while the sum is 31.

The square root of 21618814 is about 4649.6036390213. The cubic root of 21618814 is about 278.5761647484.

The spelling of 21618814 in words is "twenty-one million, six hundred eighteen thousand, eight hundred fourteen".