605 has 6 divisors (see below), whose sum is σ = 798. Its totient is φ = 440.

The previous prime is 601. The next prime is 607. The reversal of 605 is 506.

605 = T_{13} + T_{14} + ... +
T_{17}.

605 is nontrivially palindromic in base 14.

It can be written as a sum of positive squares in only one way, i.e., 484 + 121 = 22^2 + 11^2 .

It is not a de Polignac number, because 605 - 2^{2} = 601 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (11).

It is an Ulam number.

It is a Duffinian number.

605 is an undulating number in base 14.

It is a plaindrome in base 6, base 8, base 13 and base 16.

It is a nialpdrome in base 5, base 9 and base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (601) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50 + ... + 60.

It is an arithmetic number, because the mean of its divisors is an integer number (133).

It is an amenable number.

605 is a deficient number, since it is larger than the sum of its proper divisors (193).

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

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

The sum of its prime factors is 27 (or 16 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 11.

The square root of 605 is about 24.5967477525. The cubic root of 605 is about 8.4576905581.

Adding to 605 its sum of digits (11), we get a palindrome (616).

605 divided by its sum of digits (11) gives a palindrome (55).

Subtracting from 605 its product of nonzero digits (30), we obtain a palindrome (575).

Adding to 605 its reverse (506), we get a palindrome (1111).

Subtracting from 605 its reverse (506), we obtain a palindrome (99).

It can be divided in two parts, 60 and 5, that multiplied together give a triangular number (300 = T_{24}).

The spelling of 605 in words is "six hundred five", and thus it is an aban number and an oban number.

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