211404105661 has 8 divisors (see below), whose sum is σ = 241644695040. Its totient is φ = 181173517008.

The previous prime is 211404105641. The next prime is 211404105691. The reversal of 211404105661 is 166501404112.

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

It is a cyclic number.

It is not a de Polignac number, because 211404105661 - 2⁵ = 211404105629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211404105641) 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, 2454826 + ... + 2539483.

It is an arithmetic number, because the mean of its divisors is an integer number (30205586880).

Almost surely, 2^211404105661 is an apocalyptic number.

It is an amenable number.

211404105661 is a deficient number, since it is larger than the sum of its proper divisors (30240589379).

211404105661 is an equidigital number, since it uses as much as digits as its factorization.

211404105661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5000363.

The product of its (nonzero) digits is 5760, while the sum is 31.

Adding to 211404105661 its reverse (166501404112), we get a palindrome (377905509773).

The spelling of 211404105661 in words is "two hundred eleven billion, four hundred four million, one hundred five thousand, six hundred sixty-one".