347406821 has 2 divisors, whose sum is σ = 347406822. Its totient is φ = 347406820.

The previous prime is 347406803. The next prime is 347406823. The reversal of 347406821 is 128604743.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 292068100 + 55338721 = 17090^2 + 7439^2 .

It is an emirp because it is prime and its reverse (128604743) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 347406821 - 2¹⁴ = 347390437 is a prime.

Together with 347406823, 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 (347406823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 173703410 + 173703411.

It is an arithmetic number, because the mean of its divisors is an integer number (173703411).

Almost surely, 2^347406821 is an apocalyptic number.

It is an amenable number.

347406821 is a deficient number, since it is larger than the sum of its proper divisors (1).

347406821 is an equidigital number, since it uses as much as digits as its factorization.

347406821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 347406821 is about 18638.8524593120. The cubic root of 347406821 is about 702.9850896626.

The spelling of 347406821 in words is "three hundred forty-seven million, four hundred six thousand, eight hundred twenty-one".