340290721 has 2 divisors, whose sum is σ = 340290722. Its totient is φ = 340290720.

The previous prime is 340290677. The next prime is 340290767. The reversal of 340290721 is 127092043.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 327610000 + 12680721 = 18100^2 + 3561^2 .

It is a cyclic number.

It is not a de Polignac number, because 340290721 - 2⁷ = 340290593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 340290721.

It is not a weakly prime, because it can be changed into another prime (340290791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170145360 + 170145361.

It is an arithmetic number, because the mean of its divisors is an integer number (170145361).

Almost surely, 2^340290721 is an apocalyptic number.

It is an amenable number.

340290721 is a deficient number, since it is larger than the sum of its proper divisors (1).

340290721 is an equidigital number, since it uses as much as digits as its factorization.

340290721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 340290721 is about 18446.9705100865. The cubic root of 340290721 is about 698.1520790513.

The spelling of 340290721 in words is "three hundred forty million, two hundred ninety thousand, seven hundred twenty-one".