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1969 = 11179
BaseRepresentation
bin11110110001
32200221
4132301
530334
613041
75512
oct3661
92627
101969
111530
121181
13b86
14a09
158b4
hex7b1

1969 has 4 divisors (see below), whose sum is σ = 2160. Its totient is φ = 1780.

The previous prime is 1951. The next prime is 1973. The reversal of 1969 is 9691.

It can be divided in two parts, 196 and 9, that multiplied together give a square (1764 = 422).

1969 = 82 + 92 + ... + 182.

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: 9691 = 11881.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-1969 is a prime.

It is a super-2 number, since 2×19692 = 7753922, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (1949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79 + ... + 100.

It is an arithmetic number, because the mean of its divisors is an integer number (540).

21969 is an apocalyptic number.

It is an amenable number.

1969 is a deficient number, since it is larger than the sum of its proper divisors (191).

1969 is a wasteful number, since it uses less digits than its factorization.

1969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190.

The product of its digits is 486, while the sum is 25.

The square root of 1969 is about 44.3734154647. The cubic root of 1969 is about 12.5337753227.

The spelling of 1969 in words is "one thousand, nine hundred sixty-nine".

Divisors: 1 11 179 1969