243121124405 has 4 divisors (see below), whose sum is σ = 291745349292. Its totient is φ = 194496899520.

The previous prime is 243121124381. The next prime is 243121124429. The reversal of 243121124405 is 504421121342.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 504421121342 = 2 ⋅252210560671.

It is an interprime number because it is at equal distance from previous prime (243121124381) and next prime (243121124429).

It can be written as a sum of positive squares in 2 ways, for example, as 48894938884 + 194226185521 = 221122^2 + 440711^2 .

It is a de Polignac number, because none of the positive numbers 2^k-243121124405 is a prime.

It is a super-2 number, since 2×243121124405² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24312112436 + ... + 24312112445.

It is an arithmetic number, because the mean of its divisors is an integer number (72936337323).

Almost surely, 2^243121124405 is an apocalyptic number.

It is an amenable number.

243121124405 is a deficient number, since it is larger than the sum of its proper divisors (48624224887).

243121124405 is an equidigital number, since it uses as much as digits as its factorization.

243121124405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48624224886.

The product of its (nonzero) digits is 7680, while the sum is 29.

Adding to 243121124405 its reverse (504421121342), we get a palindrome (747542245747).

The spelling of 243121124405 in words is "two hundred forty-three billion, one hundred twenty-one million, one hundred twenty-four thousand, four hundred five".