21321230506 has 8 divisors (see below), whose sum is σ = 33372360864. Its totient is φ = 10197110220.

The previous prime is 21321230503. The next prime is 21321230519. The reversal of 21321230506 is 60503212312.

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

It is not an unprimeable number, because it can be changed into a prime (21321230503) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 231752460 + ... + 231752551.

It is an arithmetic number, because the mean of its divisors is an integer number (4171545108).

Almost surely, 2^21321230506 is an apocalyptic number.

21321230506 is a deficient number, since it is larger than the sum of its proper divisors (12051130358).

21321230506 is a wasteful number, since it uses less digits than its factorization.

21321230506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463505036.

The product of its (nonzero) digits is 2160, while the sum is 25.

Adding to 21321230506 its reverse (60503212312), we get a palindrome (81824442818).

The spelling of 21321230506 in words is "twenty-one billion, three hundred twenty-one million, two hundred thirty thousand, five hundred six".