21166301 has 4 divisors (see below), whose sum is σ = 22794492. Its totient is φ = 19538112.

The previous prime is 21166297. The next prime is 21166303. The reversal of 21166301 is 10366112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14638276 + 6528025 = 3826^2 + 2555^2 .

It is a cyclic number.

It is not a de Polignac number, because 21166301 - 2² = 21166297 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 814076 + ... + 814101.

It is an arithmetic number, because the mean of its divisors is an integer number (5698623).

Almost surely, 2^21166301 is an apocalyptic number.

It is an amenable number.

21166301 is a deficient number, since it is larger than the sum of its proper divisors (1628191).

21166301 is a wasteful number, since it uses less digits than its factorization.

21166301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1628190.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21166301 is about 4600.6848403254. The cubic root of 21166301 is about 276.6187764078.

The spelling of 21166301 in words is "twenty-one million, one hundred sixty-six thousand, three hundred one".