21500034211 has 4 divisors (see below), whose sum is σ = 21820930312. Its totient is φ = 21179138112.

The previous prime is 21500034209. The next prime is 21500034223. The reversal of 21500034211 is 11243000512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21500034211 - 2¹ = 21500034209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21500035211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160447950 + ... + 160448083.

It is an arithmetic number, because the mean of its divisors is an integer number (5455232578).

Almost surely, 2^21500034211 is an apocalyptic number.

21500034211 is a deficient number, since it is larger than the sum of its proper divisors (320896101).

21500034211 is an equidigital number, since it uses as much as digits as its factorization.

21500034211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320896100.

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21500034211 its reverse (11243000512), we get a palindrome (32743034723).

The spelling of 21500034211 in words is "twenty-one billion, five hundred million, thirty-four thousand, two hundred eleven".