243121535551 has 8 divisors (see below), whose sum is σ = 247000183920. Its totient is φ = 239270892288.

The previous prime is 243121535513. The next prime is 243121535597. The reversal of 243121535551 is 155535121342.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243121535551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243121535551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243121538551) 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, 6983776 + ... + 7018501.

It is an arithmetic number, because the mean of its divisors is an integer number (30875022990).

Almost surely, 2^243121535551 is an apocalyptic number.

243121535551 is a deficient number, since it is larger than the sum of its proper divisors (3878648369).

243121535551 is a wasteful number, since it uses less digits than its factorization.

243121535551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14002553.

The product of its digits is 90000, while the sum is 37.

Adding to 243121535551 its reverse (155535121342), we get a palindrome (398656656893).

The spelling of 243121535551 in words is "two hundred forty-three billion, one hundred twenty-one million, five hundred thirty-five thousand, five hundred fifty-one".