243777665868 has 192 divisors, whose sum is σ = 643734981120. Its totient is φ = 71153510400.

The previous prime is 243777665867. The next prime is 243777665869. The reversal of 243777665868 is 868566777342.

It is an interprime number because it is at equal distance from previous prime (243777665867) and next prime (243777665869).

It is not an unprimeable number, because it can be changed into a prime (243777665867) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 235989480 + ... + 235990512.

It is an arithmetic number, because the mean of its divisors is an integer number (3352786360).

Almost surely, 2^243777665868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243777665868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321867490560).

243777665868 is an abundant number, since it is smaller than the sum of its proper divisors (399957315252).

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

243777665868 is a wasteful number, since it uses less digits than its factorization.

243777665868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1528 (or 1526 counting only the distinct ones).

The product of its digits is 568995840, while the sum is 69.

The spelling of 243777665868 in words is "two hundred forty-three billion, seven hundred seventy-seven million, six hundred sixty-five thousand, eight hundred sixty-eight".