340978621 has 2 divisors, whose sum is σ = 340978622. Its totient is φ = 340978620.

The previous prime is 340978619. The next prime is 340978633. The reversal of 340978621 is 126879043.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 224100900 + 116877721 = 14970^2 + 10811^2 .

It is an emirp because it is prime and its reverse (126879043) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 340978621 - 2¹ = 340978619 is a prime.

Together with 340978619, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (340978601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170489310 + 170489311.

It is an arithmetic number, because the mean of its divisors is an integer number (170489311).

Almost surely, 2^340978621 is an apocalyptic number.

It is an amenable number.

340978621 is a deficient number, since it is larger than the sum of its proper divisors (1).

340978621 is an equidigital number, since it uses as much as digits as its factorization.

340978621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 340978621 is about 18465.6064346666. The cubic root of 340978621 is about 698.6222021285.

The spelling of 340978621 in words is "three hundred forty million, nine hundred seventy-eight thousand, six hundred twenty-one".