21168805 has 8 divisors (see below), whose sum is σ = 29031552. Its totient is φ = 14515728.

The previous prime is 21168803. The next prime is 21168817. The reversal of 21168805 is 50886112.

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 21168805 - 2¹ = 21168803 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 7 ways as a sum of consecutive naturals, for example, 302377 + ... + 302446.

It is an arithmetic number, because the mean of its divisors is an integer number (3628944).

Almost surely, 2^21168805 is an apocalyptic number.

It is an amenable number.

21168805 is a deficient number, since it is larger than the sum of its proper divisors (7862747).

21168805 is an equidigital number, since it uses as much as digits as its factorization.

21168805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604835.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 21168805 is about 4600.9569656757. The cubic root of 21168805 is about 276.6296840940.

The spelling of 21168805 in words is "twenty-one million, one hundred sixty-eight thousand, eight hundred five".