243121240451 has 4 divisors (see below), whose sum is σ = 243123861552. Its totient is φ = 243118619352.

The previous prime is 243121240379. The next prime is 243121240489. The reversal of 243121240451 is 154042121342.

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: 154042121342 = 2 ⋅77021060671.

It is a cyclic number.

It is not a de Polignac number, because 243121240451 - 2³⁴ = 225941371267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243121240651) 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, 1166111 + ... + 1358696.

It is an arithmetic number, because the mean of its divisors is an integer number (60780965388).

Almost surely, 2^243121240451 is an apocalyptic number.

243121240451 is a deficient number, since it is larger than the sum of its proper divisors (2621101).

243121240451 is an equidigital number, since it uses as much as digits as its factorization.

243121240451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2621100.

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

Adding to 243121240451 its reverse (154042121342), we get a palindrome (397163361793).

The spelling of 243121240451 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred forty thousand, four hundred fifty-one".