21131833 has 8 divisors (see below), whose sum is σ = 22462920. Its totient is φ = 19810560.

The previous prime is 21131827. The next prime is 21131881. The reversal of 21131833 is 33813112.

It can be written as a sum of positive squares in 4 ways, for example, as 944784 + 20187049 = 972^2 + 4493^2 .

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 21131833 - 2¹⁷ = 21000761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131813) 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 7 ways as a sum of consecutive naturals, for example, 2263 + ... + 6883.

It is an arithmetic number, because the mean of its divisors is an integer number (2807865).

Almost surely, 2^21131833 is an apocalyptic number.

It is an amenable number.

21131833 is a deficient number, since it is larger than the sum of its proper divisors (1331087).

21131833 is a wasteful number, since it uses less digits than its factorization.

21131833 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4907.

The product of its digits is 432, while the sum is 22.

The square root of 21131833 is about 4596.9373500190. The cubic root of 21131833 is about 276.4685426925.

Adding to 21131833 its reverse (33813112), we get a palindrome (54944945).

The spelling of 21131833 in words is "twenty-one million, one hundred thirty-one thousand, eight hundred thirty-three".