21021124605 has 16 divisors (see below), whose sum is σ = 36221015040. Its totient is φ = 10348861248.

The previous prime is 21021124561. The next prime is 21021124679. The reversal of 21021124605 is 50642112012.

It is not a de Polignac number, because 21021124605 - 2⁸ = 21021124349 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 (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53900125 + ... + 53900514.

It is an arithmetic number, because the mean of its divisors is an integer number (2263813440).

Almost surely, 2^21021124605 is an apocalyptic number.

It is an amenable number.

21021124605 is a deficient number, since it is larger than the sum of its proper divisors (15199890435).

21021124605 is a wasteful number, since it uses less digits than its factorization.

21021124605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107800660.

The product of its (nonzero) digits is 960, while the sum is 24.

Adding to 21021124605 its reverse (50642112012), we get a palindrome (71663236617).

The spelling of 21021124605 in words is "twenty-one billion, twenty-one million, one hundred twenty-four thousand, six hundred five".