21133344 has 48 divisors (see below), whose sum is σ = 57395520. Its totient is φ = 6800640.

The previous prime is 21133309. The next prime is 21133381. The reversal of 21133344 is 44333112.

It is a tau number, because it is divible by the number of its divisors (48).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21133344.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1012 + ... + 6579.

It is an arithmetic number, because the mean of its divisors is an integer number (1195740).

Almost surely, 2^21133344 is an apocalyptic number.

21133344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21133344 is an abundant number, since it is smaller than the sum of its proper divisors (36262176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21133344 is a wasteful number, since it uses less digits than its factorization.

21133344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7633 (or 7625 counting only the distinct ones).

The product of its digits is 864, while the sum is 21.

The square root of 21133344 is about 4597.1016956339. The cubic root of 21133344 is about 276.4751320248.

Adding to 21133344 its reverse (44333112), we get a palindrome (65466456).

The spelling of 21133344 in words is "twenty-one million, one hundred thirty-three thousand, three hundred forty-four".