385730021 has 2 divisors, whose sum is σ = 385730022. Its totient is φ = 385730020.

The previous prime is 385730011. The next prime is 385730047. The reversal of 385730021 is 120037583.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 262764100 + 122965921 = 16210^2 + 11089^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-385730021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385730011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192865010 + 192865011.

It is an arithmetic number, because the mean of its divisors is an integer number (192865011).

Almost surely, 2^385730021 is an apocalyptic number.

It is an amenable number.

385730021 is a deficient number, since it is larger than the sum of its proper divisors (1).

385730021 is an equidigital number, since it uses as much as digits as its factorization.

385730021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 385730021 is about 19640.0107179197. The cubic root of 385730021 is about 727.9381494821.

The spelling of 385730021 in words is "three hundred eighty-five million, seven hundred thirty thousand, twenty-one".