340242521 has 2 divisors, whose sum is σ = 340242522. Its totient is φ = 340242520.

The previous prime is 340242509. The next prime is 340242523. The reversal of 340242521 is 125242043.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 311028496 + 29214025 = 17636^2 + 5405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-340242521 is a prime.

Together with 340242523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (340242523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170121260 + 170121261.

It is an arithmetic number, because the mean of its divisors is an integer number (170121261).

Almost surely, 2^340242521 is an apocalyptic number.

It is an amenable number.

340242521 is a deficient number, since it is larger than the sum of its proper divisors (1).

340242521 is an equidigital number, since it uses as much as digits as its factorization.

340242521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 340242521 is about 18445.6640162397. The cubic root of 340242521 is about 698.1191145722.

Adding to 340242521 its reverse (125242043), we get a palindrome (465484564).

The spelling of 340242521 in words is "three hundred forty million, two hundred forty-two thousand, five hundred twenty-one".