21168290 has 64 divisors (see below), whose sum is σ = 45505152. Its totient is φ = 6988800.

The previous prime is 21168271. The next prime is 21168293. The reversal of 21168290 is 9286112.

It is not an unprimeable number, because it can be changed into a prime (21168293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 161525 + ... + 161655.

It is an arithmetic number, because the mean of its divisors is an integer number (711018).

Almost surely, 2^21168290 is an apocalyptic number.

21168290 is an abundant number, since it is smaller than the sum of its proper divisors (24336862).

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

21168290 is a wasteful number, since it uses less digits than its factorization.

21168290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 21168290 is about 4600.9009987175. The cubic root of 21168290 is about 276.6274407703.

The spelling of 21168290 in words is "twenty-one million, one hundred sixty-eight thousand, two hundred ninety".