340343021 has 2 divisors, whose sum is σ = 340343022. Its totient is φ = 340343020.

The previous prime is 340342999. The next prime is 340343039. The reversal of 340343021 is 120343043.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 331640521 + 8702500 = 18211^2 + 2950^2 .

It is an emirp because it is prime and its reverse (120343043) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 340343021 - 2⁶ = 340342957 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 340342984 and 340343002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (340346021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170171510 + 170171511.

It is an arithmetic number, because the mean of its divisors is an integer number (170171511).

Almost surely, 2^340343021 is an apocalyptic number.

It is an amenable number.

340343021 is a deficient number, since it is larger than the sum of its proper divisors (1).

340343021 is an equidigital number, since it uses as much as digits as its factorization.

340343021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 340343021 is about 18448.3880325626. The cubic root of 340343021 is about 698.1878440419.

Adding to 340343021 its reverse (120343043), we get a palindrome (460686064).

The spelling of 340343021 in words is "three hundred forty million, three hundred forty-three thousand, twenty-one".