266531985 has 32 divisors (see below), whose sum is σ = 474917760. Its totient is φ = 141825600.

The previous prime is 266531977. The next prime is 266531987. The reversal of 266531985 is 589135662.

266531985 is a `hidden beast` number, since 26 + 6 + 531 + 98 + 5 = 666.

It is not a de Polignac number, because 266531985 - 2³ = 266531977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 266531985.

It is not an unprimeable number, because it can be changed into a prime (266531987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64275 + ... + 68295.

It is an arithmetic number, because the mean of its divisors is an integer number (14841180).

Almost surely, 2^266531985 is an apocalyptic number.

It is an amenable number.

266531985 is a deficient number, since it is larger than the sum of its proper divisors (208385775).

266531985 is a wasteful number, since it uses less digits than its factorization.

266531985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4526 (or 4520 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 266531985 is about 16325.8073307264. The cubic root of 266531985 is about 643.5512100562.

The spelling of 266531985 in words is "two hundred sixty-six million, five hundred thirty-one thousand, nine hundred eighty-five".