21166141 has 4 divisors (see below), whose sum is σ = 22086432. Its totient is φ = 20245852.

The previous prime is 21166129. The next prime is 21166147. The reversal of 21166141 is 14166112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21166141 - 2¹¹ = 21164093 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 (21166147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 460111 + ... + 460156.

It is an arithmetic number, because the mean of its divisors is an integer number (5521608).

Almost surely, 2^21166141 is an apocalyptic number.

It is an amenable number.

21166141 is a deficient number, since it is larger than the sum of its proper divisors (920291).

21166141 is an equidigital number, since it uses as much as digits as its factorization.

21166141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920290.

The product of its digits is 288, while the sum is 22.

The square root of 21166141 is about 4600.6674515770. The cubic root of 21166141 is about 276.6180794018.

The spelling of 21166141 in words is "twenty-one million, one hundred sixty-six thousand, one hundred forty-one".