243121241513 has 4 divisors (see below), whose sum is σ = 243129708228. Its totient is φ = 243112774800.

The previous prime is 243121241507. The next prime is 243121241617. The reversal of 243121241513 is 315142121342.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34535390569 + 208585850944 = 185837^2 + 456712^2 .

It is a cyclic number.

It is not a de Polignac number, because 243121241513 - 2¹⁰ = 243121240489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243121241213) 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, 4190138 + ... + 4247763.

It is an arithmetic number, because the mean of its divisors is an integer number (60782427057).

Almost surely, 2^243121241513 is an apocalyptic number.

It is an amenable number.

243121241513 is a deficient number, since it is larger than the sum of its proper divisors (8466715).

243121241513 is an equidigital number, since it uses as much as digits as its factorization.

243121241513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8466714.

The product of its digits is 5760, while the sum is 29.

Adding to 243121241513 its reverse (315142121342), we get a palindrome (558263362855).

The spelling of 243121241513 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred forty-one thousand, five hundred thirteen".