21854893 has 4 divisors (see below), whose sum is σ = 22608540. Its totient is φ = 21101248.

The previous prime is 21854891. The next prime is 21854909. The reversal of 21854893 is 39845812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7086244 + 14768649 = 2662^2 + 3843^2 .

It is a cyclic number.

It is not a de Polignac number, because 21854893 - 2¹ = 21854891 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854891) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376780 + ... + 376837.

It is an arithmetic number, because the mean of its divisors is an integer number (5652135).

Almost surely, 2^21854893 is an apocalyptic number.

It is an amenable number.

21854893 is a deficient number, since it is larger than the sum of its proper divisors (753647).

21854893 is an equidigital number, since it uses as much as digits as its factorization.

21854893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753646.

The product of its digits is 69120, while the sum is 40.

The square root of 21854893 is about 4674.9217105744. The cubic root of 21854893 is about 279.5865198102.

The spelling of 21854893 in words is "twenty-one million, eight hundred fifty-four thousand, eight hundred ninety-three".