21440133 has 48 divisors (see below), whose sum is σ = 37791936. Its totient is φ = 11975040.

The previous prime is 21440129. The next prime is 21440137. The reversal of 21440133 is 33104412.

It is an interprime number because it is at equal distance from previous prime (21440129) and next prime (21440137).

It is not a de Polignac number, because 21440133 - 2² = 21440129 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440137) 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 47 ways as a sum of consecutive naturals, for example, 34441 + ... + 35057.

It is an arithmetic number, because the mean of its divisors is an integer number (787332).

Almost surely, 2^21440133 is an apocalyptic number.

It is an amenable number.

21440133 is a deficient number, since it is larger than the sum of its proper divisors (16351803).

21440133 is a wasteful number, since it uses less digits than its factorization.

21440133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 644 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21440133 is about 4630.3491229064. The cubic root of 21440133 is about 277.8065567635.

Adding to 21440133 its reverse (33104412), we get a palindrome (54544545).

The spelling of 21440133 in words is "twenty-one million, four hundred forty thousand, one hundred thirty-three".