266620121 has 4 divisors (see below), whose sum is σ = 266678244. Its totient is φ = 266562000.

The previous prime is 266620091. The next prime is 266620127. The reversal of 266620121 is 121026662.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121026662 = 2 ⋅60513331.

It can be written as a sum of positive squares in 2 ways, for example, as 234855625 + 31764496 = 15325^2 + 5636^2 .

It is a cyclic number.

It is not a de Polignac number, because 266620121 - 2¹⁴ = 266603737 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (266620127) 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, 21530 + ... + 31571.

It is an arithmetic number, because the mean of its divisors is an integer number (66669561).

Almost surely, 2^266620121 is an apocalyptic number.

It is an amenable number.

266620121 is a deficient number, since it is larger than the sum of its proper divisors (58123).

266620121 is an equidigital number, since it uses as much as digits as its factorization.

266620121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58122.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 266620121 is about 16328.5063921964. The cubic root of 266620121 is about 643.6221381021.

Adding to 266620121 its reverse (121026662), we get a palindrome (387646783).

The spelling of 266620121 in words is "two hundred sixty-six million, six hundred twenty thousand, one hundred twenty-one".