355990721 has 2 divisors, whose sum is σ = 355990722. Its totient is φ = 355990720.

The previous prime is 355990717. The next prime is 355990729. The reversal of 355990721 is 127099553.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 193071025 + 162919696 = 13895^2 + 12764^2 .

It is a cyclic number.

It is not a de Polignac number, because 355990721 - 2² = 355990717 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (355990729) 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, 177995360 + 177995361.

It is an arithmetic number, because the mean of its divisors is an integer number (177995361).

Almost surely, 2^355990721 is an apocalyptic number.

It is an amenable number.

355990721 is a deficient number, since it is larger than the sum of its proper divisors (1).

355990721 is an equidigital number, since it uses as much as digits as its factorization.

355990721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 85050, while the sum is 41.

The square root of 355990721 is about 18867.7163695027. The cubic root of 355990721 is about 708.7279484713.

The spelling of 355990721 in words is "three hundred fifty-five million, nine hundred ninety thousand, seven hundred twenty-one".