21121051305 has 16 divisors (see below), whose sum is σ = 33795869760. Its totient is φ = 11263831488.

The previous prime is 21121051283. The next prime is 21121051349. The reversal of 21121051305 is 50315012112.

It is not a de Polignac number, because 21121051305 - 2⁹ = 21121050793 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259914 + ... + 331356.

It is an arithmetic number, because the mean of its divisors is an integer number (2112241860).

Almost surely, 2^21121051305 is an apocalyptic number.

It is an amenable number.

21121051305 is a deficient number, since it is larger than the sum of its proper divisors (12674818455).

21121051305 is a wasteful number, since it uses less digits than its factorization.

21121051305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91160.

The product of its (nonzero) digits is 300, while the sum is 21.

Adding to 21121051305 its reverse (50315012112), we get a palindrome (71436063417).

The spelling of 21121051305 in words is "twenty-one billion, one hundred twenty-one million, fifty-one thousand, three hundred five".