66810 has 32 divisors (see below), whose sum is σ = 171072. Its totient is φ = 16640.

The previous prime is 66809. The next prime is 66821. The reversal of 66810 is 1866.

It is a super-2 number, since 2×66810² = 8927152200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 445 + ... + 575.

It is an arithmetic number, because the mean of its divisors is an integer number (5346).

2⁶⁶⁸¹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85536).

66810 is an abundant number, since it is smaller than the sum of its proper divisors (104262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66810 is a wasteful number, since it uses less digits than its factorization.

66810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 66810 is about 258.4763045233. The cubic root of 66810 is about 40.5770519123.

The spelling of 66810 in words is "sixty-six thousand, eight hundred ten".