385815861 has 12 divisors (see below), whose sum is σ = 557469900. Its totient is φ = 257127360.

The previous prime is 385815847. The next prime is 385815887. The reversal of 385815861 is 168518583.

385815861 is a `hidden beast` number, since 3 + 8 + 581 + 5 + 8 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 367488900 + 18326961 = 19170^2 + 4281^2 .

It is not a de Polignac number, because 385815861 - 2⁷ = 385815733 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (385815361) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37231 + ... + 46451.

It is an arithmetic number, because the mean of its divisors is an integer number (46455825).

Almost surely, 2^385815861 is an apocalyptic number.

It is an amenable number.

385815861 is a deficient number, since it is larger than the sum of its proper divisors (171654039).

385815861 is a wasteful number, since it uses less digits than its factorization.

385815861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13876 (or 13873 counting only the distinct ones).

The product of its digits is 230400, while the sum is 45.

The square root of 385815861 is about 19642.1959312089. The cubic root of 385815861 is about 727.9921437032.

The spelling of 385815861 in words is "three hundred eighty-five million, eight hundred fifteen thousand, eight hundred sixty-one".