21606788211 has 8 divisors (see below), whose sum is σ = 28809739920. Its totient is φ = 14404180992.

The previous prime is 21606788209. The next prime is 21606788237. The reversal of 21606788211 is 11288760612.

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

It is not a de Polignac number, because 21606788211 - 2¹ = 21606788209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21606788251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164035 + ... + 264803.

It is an arithmetic number, because the mean of its divisors is an integer number (3601217490).

Almost surely, 2^21606788211 is an apocalyptic number.

21606788211 is a deficient number, since it is larger than the sum of its proper divisors (7202951709).

21606788211 is a wasteful number, since it uses less digits than its factorization.

21606788211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172245.

The product of its (nonzero) digits is 64512, while the sum is 42.

The spelling of 21606788211 in words is "twenty-one billion, six hundred six million, seven hundred eighty-eight thousand, two hundred eleven".