21853191 has 8 divisors (see below), whose sum is σ = 29159680. Its totient is φ = 14557752.

The previous prime is 21853147. The next prime is 21853213. The reversal of 21853191 is 19135812.

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

It is not a de Polignac number, because 21853191 - 2¹⁴ = 21836807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21853121) 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, 4866 + ... + 8208.

It is an arithmetic number, because the mean of its divisors is an integer number (3644960).

Almost surely, 2^21853191 is an apocalyptic number.

21853191 is a deficient number, since it is larger than the sum of its proper divisors (7306489).

21853191 is a wasteful number, since it uses less digits than its factorization.

21853191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5525.

The product of its digits is 2160, while the sum is 30.

The square root of 21853191 is about 4674.7396718962. The cubic root of 21853191 is about 279.5792618076.

The spelling of 21853191 in words is "twenty-one million, eight hundred fifty-three thousand, one hundred ninety-one".