349993656721 has 2 divisors, whose sum is σ = 349993656722. Its totient is φ = 349993656720.

The previous prime is 349993656697. The next prime is 349993656731. The reversal of 349993656721 is 127656399943.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 264904766721 + 85088890000 = 514689^2 + 291700^2 .

It is a cyclic number.

It is not a de Polignac number, because 349993656721 - 2⁵ = 349993656689 is a prime.

It is not a weakly prime, because it can be changed into another prime (349993656731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 174996828360 + 174996828361.

It is an arithmetic number, because the mean of its divisors is an integer number (174996828361).

Almost surely, 2^349993656721 is an apocalyptic number.

It is an amenable number.

349993656721 is a deficient number, since it is larger than the sum of its proper divisors (1).

349993656721 is an equidigital number, since it uses as much as digits as its factorization.

349993656721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 66134880, while the sum is 64.

The spelling of 349993656721 in words is "three hundred forty-nine billion, nine hundred ninety-three million, six hundred fifty-six thousand, seven hundred twenty-one".