21853139 has 8 divisors (see below), whose sum is σ = 27245568. Its totient is φ = 17028360.

The previous prime is 21853129. The next prime is 21853141. The reversal of 21853139 is 93135812.

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

It is a cyclic number.

It is not a de Polignac number, because 21853139 - 2¹⁶ = 21787603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21853129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141827 + ... + 141980.

It is an arithmetic number, because the mean of its divisors is an integer number (3405696).

Almost surely, 2^21853139 is an apocalyptic number.

21853139 is a deficient number, since it is larger than the sum of its proper divisors (5392429).

21853139 is a wasteful number, since it uses less digits than its factorization.

21853139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283825.

The product of its digits is 6480, while the sum is 32.

The square root of 21853139 is about 4674.7341100858. The cubic root of 21853139 is about 279.5790400531.

The spelling of 21853139 in words is "twenty-one million, eight hundred fifty-three thousand, one hundred thirty-nine".