243216649 has 8 divisors (see below), whose sum is σ = 270957960. Its totient is φ = 216765696.

The previous prime is 243216641. The next prime is 243216661. The reversal of 243216649 is 946612342.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 480249 + 242736400 = 693^2 + 15580^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 243216649 - 2³ = 243216641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (243216641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322192 + ... + 322945.

It is an arithmetic number, because the mean of its divisors is an integer number (33869745).

Almost surely, 2^243216649 is an apocalyptic number.

243216649 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

243216649 is a deficient number, since it is larger than the sum of its proper divisors (27741311).

243216649 is a wasteful number, since it uses less digits than its factorization.

243216649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645179.

The product of its digits is 62208, while the sum is 37.

The square root of 243216649 is about 15595.4047398585. The cubic root of 243216649 is about 624.2105437139.

The spelling of 243216649 in words is "two hundred forty-three million, two hundred sixteen thousand, six hundred forty-nine".