21033523 has 8 divisors (see below), whose sum is σ = 25083648. Its totient is φ = 17244744.

The previous prime is 21033521. The next prime is 21033541. The reversal of 21033523 is 32533012.

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 21033523 - 2¹ = 21033521 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21033523.

It is not an unprimeable number, because it can be changed into a prime (21033521) 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, 65161 + ... + 65482.

It is an arithmetic number, because the mean of its divisors is an integer number (3135456).

Almost surely, 2^21033523 is an apocalyptic number.

21033523 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21033523 is a deficient number, since it is larger than the sum of its proper divisors (4050125).

21033523 is a wasteful number, since it uses less digits than its factorization.

21033523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130673.

The product of its (nonzero) digits is 540, while the sum is 19.

The square root of 21033523 is about 4586.2318955761. The cubic root of 21033523 is about 276.0391450114.

Adding to 21033523 its reverse (32533012), we get a palindrome (53566535).

It can be divided in two parts, 210 and 33523, that added together give a palindrome (33733).

The spelling of 21033523 in words is "twenty-one million, thirty-three thousand, five hundred twenty-three".