660138 has 8 divisors (see below), whose sum is σ = 1320288. Its totient is φ = 220044.

The previous prime is 660137. The next prime is 660157. The reversal of 660138 is 831066.

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

660138 is an admirable number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 660138.

It is not an unprimeable number, because it can be changed into a prime (660131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55006 + ... + 55017.

It is an arithmetic number, because the mean of its divisors is an integer number (165036).

2⁶⁶⁰¹³⁸ is an apocalyptic number.

660138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

660138 is a wasteful number, since it uses less digits than its factorization.

660138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110028.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 660138 is about 812.4887691531. The cubic root of 660138 is about 87.0719447166.

The spelling of 660138 in words is "six hundred sixty thousand, one hundred thirty-eight".