385705561 has 4 divisors (see below), whose sum is σ = 402475392. Its totient is φ = 368935732.

The previous prime is 385705519. The next prime is 385705577. The reversal of 385705561 is 165507583.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165507583 = 12589 ⋅13147.

It is not a de Polignac number, because 385705561 - 2¹⁷ = 385574489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (385705261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8384881 + ... + 8384926.

It is an arithmetic number, because the mean of its divisors is an integer number (100618848).

Almost surely, 2^385705561 is an apocalyptic number.

It is an amenable number.

385705561 is a deficient number, since it is larger than the sum of its proper divisors (16769831).

385705561 is a wasteful number, since it uses less digits than its factorization.

385705561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16769830.

The product of its (nonzero) digits is 126000, while the sum is 40.

The square root of 385705561 is about 19639.3879996297. The cubic root of 385705561 is about 727.9227624302.

The spelling of 385705561 in words is "three hundred eighty-five million, seven hundred five thousand, five hundred sixty-one".