6661985 has 16 divisors (see below), whose sum is σ = 8873280. Its totient is φ = 4760640.

The previous prime is 6661957. The next prime is 6661987. The reversal of 6661985 is 5891666.

It is not a de Polignac number, because 6661985 - 2¹⁴ = 6645601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6661987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2219 + ... + 4271.

It is an arithmetic number, because the mean of its divisors is an integer number (554580).

Almost surely, 2^6661985 is an apocalyptic number.

It is an amenable number.

6661985 is a deficient number, since it is larger than the sum of its proper divisors (2211295).

6661985 is a wasteful number, since it uses less digits than its factorization.

6661985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2128.

The product of its digits is 77760, while the sum is 41.

The square root of 6661985 is about 2581.0821373990. The cubic root of 6661985 is about 188.1631392893.

The spelling of 6661985 in words is "six million, six hundred sixty-one thousand, nine hundred eighty-five".