6661320 has 32 divisors (see below), whose sum is σ = 19984320. Its totient is φ = 1776320.

The previous prime is 6661313. The next prime is 6661327. The reversal of 6661320 is 231666.

It is an interprime number because it is at equal distance from previous prime (6661313) and next prime (6661327).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (6661327) 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, 27636 + ... + 27875.

It is an arithmetic number, because the mean of its divisors is an integer number (624510).

Almost surely, 2^6661320 is an apocalyptic number.

6661320 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6661320 is an abundant number, since it is smaller than the sum of its proper divisors (13323000).

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

6661320 is a wasteful number, since it uses less digits than its factorization.

6661320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55525 (or 55521 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 6661320 is about 2580.9533122472. The cubic root of 6661320 is about 188.1568782599.

Adding to 6661320 its reverse (231666), we get a palindrome (6892986).

The spelling of 6661320 in words is "six million, six hundred sixty-one thousand, three hundred twenty".