385438721 has 2 divisors, whose sum is σ = 385438722. Its totient is φ = 385438720.

The previous prime is 385438667. The next prime is 385438727. The reversal of 385438721 is 127834583.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 311134321 + 74304400 = 17639^2 + 8620^2 .

It is a cyclic number.

It is not a de Polignac number, because 385438721 - 2¹⁸ = 385176577 is a prime.

It is a super-2 number, since 2×385438721² = 297126015292231682, which contains 22 as substring.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (385438727) 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, 192719360 + 192719361.

It is an arithmetic number, because the mean of its divisors is an integer number (192719361).

Almost surely, 2^385438721 is an apocalyptic number.

It is an amenable number.

385438721 is a deficient number, since it is larger than the sum of its proper divisors (1).

385438721 is an equidigital number, since it uses as much as digits as its factorization.

385438721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 161280, while the sum is 41.

The square root of 385438721 is about 19632.5933335359. The cubic root of 385438721 is about 727.7548591211.

The spelling of 385438721 in words is "three hundred eighty-five million, four hundred thirty-eight thousand, seven hundred twenty-one".