340393021 has 2 divisors, whose sum is σ = 340393022. Its totient is φ = 340393020.

The previous prime is 340393019. The next prime is 340393153. The reversal of 340393021 is 120393043.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 281870521 + 58522500 = 16789^2 + 7650^2 .

It is a cyclic number.

It is not a de Polignac number, because 340393021 - 2¹ = 340393019 is a prime.

Together with 340393019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (340399021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170196510 + 170196511.

It is an arithmetic number, because the mean of its divisors is an integer number (170196511).

Almost surely, 2^340393021 is an apocalyptic number.

It is an amenable number.

340393021 is a deficient number, since it is larger than the sum of its proper divisors (1).

340393021 is an equidigital number, since it uses as much as digits as its factorization.

340393021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 25.

The square root of 340393021 is about 18449.7431147428. The cubic root of 340393021 is about 698.2220327679. Note that the first 3 decimals are identical.

The spelling of 340393021 in words is "three hundred forty million, three hundred ninety-three thousand, twenty-one".