51669 has 6 divisors (see below), whose sum is σ = 74646. Its totient is φ = 34440.

The previous prime is 51659. The next prime is 51673. The reversal of 51669 is 96615.

It can be written as a sum of positive squares in only one way, i.e., 44100 + 7569 = 210^2 + 87^2 .

It is not a de Polignac number, because 51669 - 2⁵ = 51637 is a prime.

It is a super-2 number, since 2×51669² = 5339371122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51659) 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, 2862 + ... + 2879.

It is an arithmetic number, because the mean of its divisors is an integer number (12441).

2⁵¹⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

51669 is a deficient number, since it is larger than the sum of its proper divisors (22977).

51669 is a wasteful number, since it uses less digits than its factorization.

51669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5747 (or 5744 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 51669 is about 227.3081608742. The cubic root of 51669 is about 37.2457467029.

It can be divided in two parts, 516 and 69, that added together give a palindrome (585).

The spelling of 51669 in words is "fifty-one thousand, six hundred sixty-nine".