670345421 has 2 divisors, whose sum is σ = 670345422. Its totient is φ = 670345420.

The previous prime is 670345399. The next prime is 670345483. The reversal of 670345421 is 124543076.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 661261225 + 9084196 = 25715^2 + 3014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-670345421 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (670345721) 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, 335172710 + 335172711.

It is an arithmetic number, because the mean of its divisors is an integer number (335172711).

Almost surely, 2^670345421 is an apocalyptic number.

It is an amenable number.

670345421 is a deficient number, since it is larger than the sum of its proper divisors (1).

670345421 is an equidigital number, since it uses as much as digits as its factorization.

670345421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 670345421 is about 25891.0297400470. The cubic root of 670345421 is about 875.1843621318.

Adding to 670345421 its reverse (124543076), we get a palindrome (794888497).

The spelling of 670345421 in words is "six hundred seventy million, three hundred forty-five thousand, four hundred twenty-one".