243734517421 has 4 divisors (see below), whose sum is σ = 243762442144. Its totient is φ = 243706592700.

The previous prime is 243734517391. The next prime is 243734517449. The reversal of 243734517421 is 124715437342.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 243734517421 - 2¹³ = 243734509229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243734517821) 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, 13949265 + ... + 13966726.

It is an arithmetic number, because the mean of its divisors is an integer number (60940610536).

Almost surely, 2^243734517421 is an apocalyptic number.

It is an amenable number.

243734517421 is a deficient number, since it is larger than the sum of its proper divisors (27924723).

243734517421 is an equidigital number, since it uses as much as digits as its factorization.

243734517421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27924722.

The product of its digits is 564480, while the sum is 43.

The spelling of 243734517421 in words is "two hundred forty-three billion, seven hundred thirty-four million, five hundred seventeen thousand, four hundred twenty-one".