660040 has 32 divisors (see below), whose sum is σ = 1539000. Its totient is φ = 254464.

The previous prime is 660029. The next prime is 660047. The reversal of 660040 is 40066.

660040 = T₃₉ + T₄₀ + ... + T₁₅₈.

It can be written as a sum of positive squares in 4 ways, for example, as 427716 + 232324 = 654^2 + 482^2 .

It is a junction number, because it is equal to n+sod(n) for n = 659996 and 660023.

It is not an unprimeable number, because it can be changed into a prime (660047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 876 + ... + 1444.

2⁶⁶⁰⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 660040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (769500).

660040 is an abundant number, since it is smaller than the sum of its proper divisors (878960).

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

660040 is a wasteful number, since it uses less digits than its factorization.

660040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609 (or 605 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 660040 is about 812.4284583888. The cubic root of 660040 is about 87.0676357828.

The spelling of 660040 in words is "six hundred sixty thousand, forty".