6661020 has 48 divisors (see below), whose sum is σ = 19635840. Its totient is φ = 1682496.

The previous prime is 6661013. The next prime is 6661021. The reversal of 6661020 is 201666.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661021) 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, 1782 + ... + 4061.

It is an arithmetic number, because the mean of its divisors is an integer number (409080).

Almost surely, 2^6661020 is an apocalyptic number.

6661020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6661020 is an abundant number, since it is smaller than the sum of its proper divisors (12974820).

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

6661020 is a wasteful number, since it uses less digits than its factorization.

6661020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5874 (or 5872 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 6661020 is about 2580.8951935327. The cubic root of 6661020 is about 188.1540535990.

Adding to 6661020 its reverse (201666), we get a palindrome (6862686).

The spelling of 6661020 in words is "six million, six hundred sixty-one thousand, twenty".