21871133 has 8 divisors (see below), whose sum is σ = 23152800. Its totient is φ = 20624688.

The previous prime is 21871117. The next prime is 21871141. The reversal of 21871133 is 33117812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21871133 - 2⁴ = 21871117 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 (21871153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7523 + ... + 10016.

It is an arithmetic number, because the mean of its divisors is an integer number (2894100).

Almost surely, 2^21871133 is an apocalyptic number.

It is an amenable number.

21871133 is a deficient number, since it is larger than the sum of its proper divisors (1281667).

21871133 is a wasteful number, since it uses less digits than its factorization.

21871133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17611.

The product of its digits is 1008, while the sum is 26.

The square root of 21871133 is about 4676.6583155069. The cubic root of 21871133 is about 279.6557546629.

Adding to 21871133 its reverse (33117812), we get a palindrome (54988945).

The spelling of 21871133 in words is "twenty-one million, eight hundred seventy-one thousand, one hundred thirty-three".