561385 has 16 divisors (see below), whose sum is σ = 751680. Its totient is φ = 399040.

The previous prime is 561377. The next prime is 561389. The reversal of 561385 is 583165.

It is not a de Polignac number, because 561385 - 2³ = 561377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3159 + ... + 3331.

It is an arithmetic number, because the mean of its divisors is an integer number (46980).

2⁵⁶¹³⁸⁵ is an apocalyptic number.

561385 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

561385 is a deficient number, since it is larger than the sum of its proper divisors (190295).

561385 is a wasteful number, since it uses less digits than its factorization.

561385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248.

The product of its digits is 3600, while the sum is 28.

The square root of 561385 is about 749.2562979382. The cubic root of 561385 is about 82.4936021975.

It can be divided in two parts, 561 and 385, that added together give a triangular number (946 = T₄₃).

The spelling of 561385 in words is "five hundred sixty-one thousand, three hundred eighty-five".