66240 has 84 divisors (see below), whose sum is σ = 237744. Its totient is φ = 16896.

The previous prime is 66239. The next prime is 66271. The reversal of 66240 is 4266.

66240 = T₂₉ + T₃₀ + ... + T₇₄.

66240 is a `hidden beast` number, since 662 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2869 + ... + 2891.

2⁶⁶²⁴⁰ is an apocalyptic number.

66240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118872).

66240 is an abundant number, since it is smaller than the sum of its proper divisors (171504).

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

66240 is a wasteful number, since it uses less digits than its factorization.

66240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 66240 is about 257.3713270743. The cubic root of 66240 is about 40.4613256780.

The spelling of 66240 in words is "sixty-six thousand, two hundred forty".