21121052305 has 16 divisors (see below), whose sum is σ = 25539494400. Its totient is φ = 16767444352.

The previous prime is 21121052291. The next prime is 21121052311. The reversal of 21121052305 is 50325012112.

It is a cyclic number.

It is not a de Polignac number, because 21121052305 - 2⁵ = 21121052273 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, 3489792 + ... + 3495838.

It is an arithmetic number, because the mean of its divisors is an integer number (1596218400).

Almost surely, 2^21121052305 is an apocalyptic number.

It is an amenable number.

21121052305 is a deficient number, since it is larger than the sum of its proper divisors (4418442095).

21121052305 is a wasteful number, since it uses less digits than its factorization.

21121052305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11288.

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21121052305 its reverse (50325012112), we get a palindrome (71446064417).

The spelling of 21121052305 in words is "twenty-one billion, one hundred twenty-one million, fifty-two thousand, three hundred five".