21332523 has 8 divisors (see below), whose sum is σ = 29680128. Its totient is φ = 13603304.

The previous prime is 21332503. The next prime is 21332527. The reversal of 21332523 is 32523312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21332523 - 2²⁰ = 20283947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21332523.

It is not an unprimeable number, because it can be changed into a prime (21332527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154515 + ... + 154652.

It is an arithmetic number, because the mean of its divisors is an integer number (3710016).

Almost surely, 2^21332523 is an apocalyptic number.

21332523 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21332523 is a deficient number, since it is larger than the sum of its proper divisors (8347605).

21332523 is a wasteful number, since it uses less digits than its factorization.

21332523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309193.

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

The square root of 21332523 is about 4618.7144315275. The cubic root of 21332523 is about 277.3409981098.

Adding to 21332523 its reverse (32523312), we get a palindrome (53855835).

It can be divided in two parts, 2133 and 2523, that added together give a triangular number (4656 = T₉₆).

The spelling of 21332523 in words is "twenty-one million, three hundred thirty-two thousand, five hundred twenty-three".