243121105525 has 12 divisors (see below), whose sum is σ = 301477051332. Its totient is φ = 194492445440.

The previous prime is 243121105459. The next prime is 243121105537. The reversal of 243121105525 is 525501121342.

It can be written as a sum of positive squares in 6 ways, for example, as 40672402276 + 202448703249 = 201674^2 + 449943^2 .

It is not a de Polignac number, because 243121105525 - 2⁹ = 243121105013 is a prime.

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 11 ways as a sum of consecutive naturals, for example, 1420989 + ... + 1582861.

It is an arithmetic number, because the mean of its divisors is an integer number (25123087611).

Almost surely, 2^243121105525 is an apocalyptic number.

243121105525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

243121105525 is a deficient number, since it is larger than the sum of its proper divisors (58355945807).

243121105525 is a wasteful number, since it uses less digits than its factorization.

243121105525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221960 (or 221955 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 31.

Adding to 243121105525 its reverse (525501121342), we get a palindrome (768622226867).

The spelling of 243121105525 in words is "two hundred forty-three billion, one hundred twenty-one million, one hundred five thousand, five hundred twenty-five".