243942835661 has 12 divisors (see below), whose sum is σ = 288075210336. Its totient is φ = 202348890360.

The previous prime is 243942835627. The next prime is 243942835757. The reversal of 243942835661 is 166538249342.

It is a happy number.

It is not a de Polignac number, because 243942835661 - 2¹⁴ = 243942819277 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243942835561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18124895 + ... + 18138348.

It is an arithmetic number, because the mean of its divisors is an integer number (24006267528).

Almost surely, 2^243942835661 is an apocalyptic number.

It is an amenable number.

243942835661 is a deficient number, since it is larger than the sum of its proper divisors (44132374675).

243942835661 is an equidigital number, since it uses as much as digits as its factorization.

243942835661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36263312 (or 36263281 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 53.

The spelling of 243942835661 in words is "two hundred forty-three billion, nine hundred forty-two million, eight hundred thirty-five thousand, six hundred sixty-one".