6661749 has 16 divisors (see below), whose sum is σ = 9195840. Its totient is φ = 4287360.

The previous prime is 6661747. The next prime is 6661751. The reversal of 6661749 is 9471666.

It is an interprime number because it is at equal distance from previous prime (6661747) and next prime (6661751).

It is not a de Polignac number, because 6661749 - 2¹ = 6661747 is a prime.

6661749 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10489 + ... + 11105.

It is an arithmetic number, because the mean of its divisors is an integer number (574740).

Almost surely, 2^6661749 is an apocalyptic number.

It is an amenable number.

6661749 is a deficient number, since it is larger than the sum of its proper divisors (2534091).

6661749 is a wasteful number, since it uses less digits than its factorization.

6661749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740.

The product of its digits is 54432, while the sum is 39.

The square root of 6661749 is about 2581.0364197353. The cubic root of 6661749 is about 188.1609173777.

It can be divided in two parts, 66617 and 49, that added together give a palindrome (66666).

The spelling of 6661749 in words is "six million, six hundred sixty-one thousand, seven hundred forty-nine".