351868686821 has 2 divisors, whose sum is σ = 351868686822. Its totient is φ = 351868686820.

The previous prime is 351868686803. The next prime is 351868686881. The reversal of 351868686821 is 128686868153.

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., 351220984321 + 647702500 = 592639^2 + 25450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-351868686821 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 (351868686881) 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, 175934343410 + 175934343411.

It is an arithmetic number, because the mean of its divisors is an integer number (175934343411).

Almost surely, 2^351868686821 is an apocalyptic number.

It is an amenable number.

351868686821 is a deficient number, since it is larger than the sum of its proper divisors (1).

351868686821 is an equidigital number, since it uses as much as digits as its factorization.

351868686821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26542080, while the sum is 62.

The spelling of 351868686821 in words is "three hundred fifty-one billion, eight hundred sixty-eight million, six hundred eighty-six thousand, eight hundred twenty-one".