21660133 has 16 divisors (see below), whose sum is σ = 25554240. Its totient is φ = 18144000.

The previous prime is 21660131. The next prime is 21660137. The reversal of 21660133 is 33106612.

It is a cyclic number.

It is not a de Polignac number, because 21660133 - 2¹ = 21660131 is a prime.

It is a super-2 number, since 2×21660133² = 938322723155378, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21660131) by changing a digit.

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, 6333 + ... + 9133.

It is an arithmetic number, because the mean of its divisors is an integer number (1597140).

Almost surely, 2^21660133 is an apocalyptic number.

It is an amenable number.

21660133 is a deficient number, since it is larger than the sum of its proper divisors (3894107).

21660133 is a wasteful number, since it uses less digits than its factorization.

21660133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2868.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21660133 is about 4654.0447999563. The cubic root of 21660133 is about 278.7535282118.

Adding to 21660133 its reverse (33106612), we get a palindrome (54766745).

The spelling of 21660133 in words is "twenty-one million, six hundred sixty thousand, one hundred thirty-three".