266121121661 has 8 divisors (see below), whose sum is σ = 267315681600. Its totient is φ = 264926757088.

The previous prime is 266121121657. The next prime is 266121121711. The reversal of 266121121661 is 166121121662.

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 266121121661 - 2² = 266121121657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266121121631) 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, 3149240 + ... + 3232638.

It is an arithmetic number, because the mean of its divisors is an integer number (33414460200).

Almost surely, 2^266121121661 is an apocalyptic number.

It is an amenable number.

266121121661 is a deficient number, since it is larger than the sum of its proper divisors (1194559939).

266121121661 is a wasteful number, since it uses less digits than its factorization.

266121121661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97683.

The product of its digits is 10368, while the sum is 35.

Subtracting from 266121121661 its reverse (166121121662), we obtain a palindrome (99999999999).

The spelling of 266121121661 in words is "two hundred sixty-six billion, one hundred twenty-one million, one hundred twenty-one thousand, six hundred sixty-one".