21232605 has 8 divisors (see below), whose sum is σ = 33972192. Its totient is φ = 11324048.

The previous prime is 21232571. The next prime is 21232639. The reversal of 21232605 is 50623212.

It is an interprime number because it is at equal distance from previous prime (21232571) and next prime (21232639).

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 21232605 - 2¹¹ = 21230557 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 707739 + ... + 707768.

It is an arithmetic number, because the mean of its divisors is an integer number (4246524).

Almost surely, 2^21232605 is an apocalyptic number.

It is an amenable number.

21232605 is a deficient number, since it is larger than the sum of its proper divisors (12739587).

21232605 is a wasteful number, since it uses less digits than its factorization.

21232605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1415515.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 21232605 is about 4607.8850897131. The cubic root of 21232605 is about 276.9073138879.

Adding to 21232605 its reverse (50623212), we get a palindrome (71855817).

The spelling of 21232605 in words is "twenty-one million, two hundred thirty-two thousand, six hundred five".