21170066111 has 4 divisors (see below), whose sum is σ = 22090503792. Its totient is φ = 20249628432.

The previous prime is 21170066107. The next prime is 21170066123. The reversal of 21170066111 is 11166007112.

It is a happy number.

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 21170066111 - 2² = 21170066107 is a prime.

It is a super-2 number, since 2×21170066111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170066011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 460218806 + ... + 460218851.

It is an arithmetic number, because the mean of its divisors is an integer number (5522625948).

Almost surely, 2^21170066111 is an apocalyptic number.

21170066111 is a deficient number, since it is larger than the sum of its proper divisors (920437681).

21170066111 is an equidigital number, since it uses as much as digits as its factorization.

21170066111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920437680.

The product of its (nonzero) digits is 504, while the sum is 26.

The spelling of 21170066111 in words is "twenty-one billion, one hundred seventy million, sixty-six thousand, one hundred eleven".