243957972129 has 4 divisors (see below), whose sum is σ = 325277296176. Its totient is φ = 162638648084.

The previous prime is 243957972113. The next prime is 243957972131. The reversal of 243957972129 is 921279759342.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 243957972129 - 2⁴ = 243957972113 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (243957972109) 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, 40659662019 + ... + 40659662024.

It is an arithmetic number, because the mean of its divisors is an integer number (81319324044).

Almost surely, 2^243957972129 is an apocalyptic number.

It is an amenable number.

243957972129 is a deficient number, since it is larger than the sum of its proper divisors (81319324047).

243957972129 is an equidigital number, since it uses as much as digits as its factorization.

243957972129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81319324046.

The product of its digits is 17146080, while the sum is 60.

The spelling of 243957972129 in words is "two hundred forty-three billion, nine hundred fifty-seven million, nine hundred seventy-two thousand, one hundred twenty-nine".