266611643 has 12 divisors (see below), whose sum is σ = 274990800. Its totient is φ = 258477120.

The previous prime is 266611637. The next prime is 266611691. The reversal of 266611643 is 346116662.

It is not a de Polignac number, because 266611643 - 2¹⁶ = 266546107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266611633) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 334121 + ... + 334917.

It is an arithmetic number, because the mean of its divisors is an integer number (22915900).

Almost surely, 2^266611643 is an apocalyptic number.

266611643 is a deficient number, since it is larger than the sum of its proper divisors (8379157).

266611643 is an equidigital number, since it uses as much as digits as its factorization.

266611643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078 (or 1037 counting only the distinct ones).

The product of its digits is 31104, while the sum is 35.

The square root of 266611643 is about 16328.2467827994. The cubic root of 266611643 is about 643.6153160534.

The spelling of 266611643 in words is "two hundred sixty-six million, six hundred eleven thousand, six hundred forty-three".