340243424021 has 4 divisors (see below), whose sum is σ = 340794872652. Its totient is φ = 339691975392.

The previous prime is 340243424011. The next prime is 340243424039. The reversal of 340243424021 is 120424342043.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120424342043 = 877 ⋅137313959.

It can be written as a sum of positive squares in 2 ways, for example, as 31007335921 + 309236088100 = 176089^2 + 556090^2 .

It is a cyclic number.

It is not a de Polignac number, because 340243424021 - 2⁶ = 340243423957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340243424011) 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, 275723390 + ... + 275724623.

It is an arithmetic number, because the mean of its divisors is an integer number (85198718163).

Almost surely, 2^340243424021 is an apocalyptic number.

It is an amenable number.

340243424021 is a deficient number, since it is larger than the sum of its proper divisors (551448631).

340243424021 is an equidigital number, since it uses as much as digits as its factorization.

340243424021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551448630.

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 340243424021 its reverse (120424342043), we get a palindrome (460667766064).

The spelling of 340243424021 in words is "three hundred forty billion, two hundred forty-three million, four hundred twenty-four thousand, twenty-one".