21854238 has 16 divisors (see below), whose sum is σ = 49952640. Its totient is φ = 6244056.

The previous prime is 21854233. The next prime is 21854251. The reversal of 21854238 is 83245812.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21854199 and 21854208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854233) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 260128 + ... + 260211.

It is an arithmetic number, because the mean of its divisors is an integer number (3122040).

Almost surely, 2^21854238 is an apocalyptic number.

21854238 is an abundant number, since it is smaller than the sum of its proper divisors (28098402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21854238 is a wasteful number, since it uses less digits than its factorization.

21854238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520351.

The product of its digits is 15360, while the sum is 33.

The square root of 21854238 is about 4674.8516554004. The cubic root of 21854238 is about 279.5837266752.

The spelling of 21854238 in words is "twenty-one million, eight hundred fifty-four thousand, two hundred thirty-eight".