243240621545 has 4 divisors (see below), whose sum is σ = 291888745860. Its totient is φ = 194592497232.

The previous prime is 243240621461. The next prime is 243240621629. The reversal of 243240621545 is 545126042342.

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

It is an interprime number because it is at equal distance from previous prime (243240621461) and next prime (243240621629).

It can be written as a sum of positive squares in 2 ways, for example, as 175500669184 + 67739952361 = 418928^2 + 260269^2 .

It is a cyclic number.

It is not a de Polignac number, because 243240621545 - 2¹⁰ = 243240620521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243240621499 and 243240621508.

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, 24324062150 + ... + 24324062159.

It is an arithmetic number, because the mean of its divisors is an integer number (72972186465).

Almost surely, 2^243240621545 is an apocalyptic number.

It is an amenable number.

243240621545 is a deficient number, since it is larger than the sum of its proper divisors (48648124315).

243240621545 is an equidigital number, since it uses as much as digits as its factorization.

243240621545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48648124314.

The product of its (nonzero) digits is 230400, while the sum is 38.

Adding to 243240621545 its reverse (545126042342), we get a palindrome (788366663887).

The spelling of 243240621545 in words is "two hundred forty-three billion, two hundred forty million, six hundred twenty-one thousand, five hundred forty-five".