369 has 6 divisors (see below), whose sum is σ = 546. Its totient is φ = 240.

The previous prime is 367. The next prime is 373. The reversal of 369 is 963.

Subtracting from 369 its sum of digits (18), we obtain a triangular number (351 = T_{26}).

It can be divided in two parts, 36 and 9, that multiplied together give a square (324 = 18^{2}).

369 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in only one way, i.e., 225 + 144 = 15^2 + 12^2 .

It is not a de Polignac number, because 369 - 2^{1} = 367 is a prime.

It is a super-2 number, since 2×369^{2} = 272322, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

369 is an undulating number in base 16.

It is a Curzon number.

It is a straight-line number, since its digits are in arithmetic progression.

It is a plaindrome in base 10, base 12, base 13 and base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12 + ... + 29.

It is an arithmetic number, because the mean of its divisors is an integer number (91).

It is the magic constant of a 9 × 9 magic square.

It is an amenable number.

369 is a deficient number, since it is larger than the sum of its proper divisors (177).

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

With its successor (370) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (44).

369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47 (or 44 counting only the distinct ones).

The product of its digits is 162, while the sum is 18.

The square root of 369 is about 19.2093727123. The cubic root of 369 is about 7.1725809001.

The spelling of 369 in words is "three hundred sixty-nine", and thus it is an aban number and an oban number.

• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.052 sec. • engine limits •