385138181 has 2 divisors, whose sum is σ = 385138182. Its totient is φ = 385138180.

The previous prime is 385138153. The next prime is 385138219. The reversal of 385138181 is 181831583.

It is an a-pointer prime, because the next prime (385138219) can be obtained adding 385138181 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199769956 + 185368225 = 14134^2 + 13615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-385138181 is a prime.

It is a super-2 number, since 2×385138181² = 296662836927977522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385138681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192569090 + 192569091.

It is an arithmetic number, because the mean of its divisors is an integer number (192569091).

Almost surely, 2^385138181 is an apocalyptic number.

It is an amenable number.

385138181 is a deficient number, since it is larger than the sum of its proper divisors (1).

385138181 is an equidigital number, since it uses as much as digits as its factorization.

385138181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 38.

The square root of 385138181 is about 19624.9377323853. The cubic root of 385138181 is about 727.5656579971.

The spelling of 385138181 in words is "three hundred eighty-five million, one hundred thirty-eight thousand, one hundred eighty-one".