21133771 has 8 divisors (see below), whose sum is σ = 22982400. Its totient is φ = 19352448.

The previous prime is 21133753. The next prime is 21133781. The reversal of 21133771 is 17733112.

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 21133771 - 2¹¹ = 21131723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21133781) 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 7 ways as a sum of consecutive naturals, for example, 16171 + ... + 17428.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^21133771 is an apocalyptic number.

21133771 is a deficient number, since it is larger than the sum of its proper divisors (1848629).

21133771 is a wasteful number, since it uses less digits than its factorization.

21133771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33653.

The product of its digits is 882, while the sum is 25.

The square root of 21133771 is about 4597.1481377045. The cubic root of 21133771 is about 276.4769940757.

Adding to 21133771 its reverse (17733112), we get a palindrome (38866883).

It can be divided in two parts, 21133 and 771, that added together give a square (21904 = 148²).

The spelling of 21133771 in words is "twenty-one million, one hundred thirty-three thousand, seven hundred seventy-one".