243991266 has 32 divisors (see below), whose sum is σ = 504672768. Its totient is φ = 78558720.

The previous prime is 243991247. The next prime is 243991271. The reversal of 243991266 is 662199342.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142930 + ... + 144626.

It is an arithmetic number, because the mean of its divisors is an integer number (15771024).

Almost surely, 2^243991266 is an apocalyptic number.

243991266 is an abundant number, since it is smaller than the sum of its proper divisors (260681502).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

243991266 is a wasteful number, since it uses less digits than its factorization.

243991266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2506.

The product of its digits is 139968, while the sum is 42.

The square root of 243991266 is about 15620.2197807841. The cubic root of 243991266 is about 624.8725209870.

The spelling of 243991266 in words is "two hundred forty-three million, nine hundred ninety-one thousand, two hundred sixty-six".