243993311 has 4 divisors (see below), whose sum is σ = 245631000. Its totient is φ = 242355624.

The previous prime is 243993287. The next prime is 243993313. The reversal of 243993311 is 113399342.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243993311 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 (243993313) 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, 818621 + ... + 818918.

It is an arithmetic number, because the mean of its divisors is an integer number (61407750).

Almost surely, 2^243993311 is an apocalyptic number.

243993311 is a deficient number, since it is larger than the sum of its proper divisors (1637689).

243993311 is a wasteful number, since it uses less digits than its factorization.

243993311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1637688.

The product of its digits is 17496, while the sum is 35.

The square root of 243993311 is about 15620.2852406734. The cubic root of 243993311 is about 624.8742667609.

The spelling of 243993311 in words is "two hundred forty-three million, nine hundred ninety-three thousand, three hundred eleven".