21453033 has 24 divisors (see below), whose sum is σ = 35029920. Its totient is φ = 11612160.

The previous prime is 21453017. The next prime is 21453037. The reversal of 21453033 is 33035412.

It is not a de Polignac number, because 21453033 - 2⁴ = 21453017 is a prime.

It is a super-3 number, since 3×21453033³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21453037) 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 23 ways as a sum of consecutive naturals, for example, 1048 + ... + 6633.

It is an arithmetic number, because the mean of its divisors is an integer number (1459580).

Almost surely, 2^21453033 is an apocalyptic number.

It is an amenable number.

21453033 is a deficient number, since it is larger than the sum of its proper divisors (13576887).

21453033 is a wasteful number, since it uses less digits than its factorization.

21453033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7717 (or 7710 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 21.

The square root of 21453033 is about 4631.7418969541. The cubic root of 21453033 is about 277.8622620472.

Adding to 21453033 its reverse (33035412), we get a palindrome (54488445).

The spelling of 21453033 in words is "twenty-one million, four hundred fifty-three thousand, thirty-three".