21168853 has 4 divisors (see below), whose sum is σ = 21179340. Its totient is φ = 21158368.

The previous prime is 21168827. The next prime is 21168871. The reversal of 21168853 is 35886112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 19158129 + 2010724 = 4377^2 + 1418^2 .

It is a cyclic number.

It is not a de Polignac number, because 21168853 - 2⁵ = 21168821 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 (21168803) 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, 1150 + ... + 6607.

It is an arithmetic number, because the mean of its divisors is an integer number (5294835).

Almost surely, 2^21168853 is an apocalyptic number.

It is an amenable number.

21168853 is a deficient number, since it is larger than the sum of its proper divisors (10487).

21168853 is an equidigital number, since it uses as much as digits as its factorization.

21168853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10486.

The product of its digits is 11520, while the sum is 34.

The square root of 21168853 is about 4600.9621819789. The cubic root of 21168853 is about 276.6298931786.

The spelling of 21168853 in words is "twenty-one million, one hundred sixty-eight thousand, eight hundred fifty-three".