21370166 has 16 divisors (see below), whose sum is σ = 32703264. Its totient is φ = 10471104.

The previous prime is 21370157. The next prime is 21370177. The reversal of 21370166 is 66107312.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28391 + ... + 29133.

It is an arithmetic number, because the mean of its divisors is an integer number (2043954).

Almost surely, 2^21370166 is an apocalyptic number.

21370166 is a deficient number, since it is larger than the sum of its proper divisors (11333098).

21370166 is a wasteful number, since it uses less digits than its factorization.

21370166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21370166 is about 4622.7876870996. The cubic root of 21370166 is about 277.5040326227.

Adding to 21370166 its reverse (66107312), we get a palindrome (87477478).

The spelling of 21370166 in words is "twenty-one million, three hundred seventy thousand, one hundred sixty-six".