65690 has 8 divisors (see below), whose sum is σ = 118260. Its totient is φ = 26272.

The previous prime is 65687. The next prime is 65699. The reversal of 65690 is 9656.

It can be written as a sum of positive squares in 2 ways, for example, as 64009 + 1681 = 253^2 + 41^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×65690² = 8630352200, which contains 22 as substring.

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

It is a Curzon number.

It is a zygodrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (65699) 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 3 ways as a sum of consecutive naturals, for example, 3275 + ... + 3294.

2⁶⁵⁶⁹⁰ is an apocalyptic number.

65690 is a deficient number, since it is larger than the sum of its proper divisors (52570).

65690 is a wasteful number, since it uses less digits than its factorization.

65690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6576.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 65690 is about 256.3006047593. The cubic root of 65690 is about 40.3490289451.

It can be divided in two parts, 65 and 690, that multiplied together give a triangular number (44850 = T₂₉₉).

The spelling of 65690 in words is "sixty-five thousand, six hundred ninety".