21701166 has 32 divisors (see below), whose sum is σ = 45271680. Its totient is φ = 6928416.

The previous prime is 21701159. The next prime is 21701179. The reversal of 21701166 is 66110712.

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 15 ways as a sum of consecutive naturals, for example, 14145 + ... + 15603.

It is an arithmetic number, because the mean of its divisors is an integer number (1414740).

Almost surely, 2^21701166 is an apocalyptic number.

21701166 is an abundant number, since it is smaller than the sum of its proper divisors (23570514).

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

21701166 is a wasteful number, since it uses less digits than its factorization.

21701166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1568.

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 21701166 is about 4658.4510301172. The cubic root of 21701166 is about 278.9294409256.

Adding to 21701166 its reverse (66110712), we get a palindrome (87811878).

The spelling of 21701166 in words is "twenty-one million, seven hundred one thousand, one hundred sixty-six".