7749 has 16 divisors (see below), whose sum is σ = 13440. Its totient is φ = 4320.

The previous prime is 7741. The next prime is 7753. The reversal of 7749 is 9477.

It is not a de Polignac number, because 7749 - 2³ = 7741 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a plaindrome in base 12 and base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169 + ... + 209.

It is an arithmetic number, because the mean of its divisors is an integer number (840).

2⁷⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

7749 is a deficient number, since it is larger than the sum of its proper divisors (5691).

7749 is a wasteful number, since it uses less digits than its factorization.

7749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57 (or 51 counting only the distinct ones).

The product of its digits is 1764, while the sum is 27.

The square root of 7749 is about 88.0284045067. The cubic root of 7749 is about 19.7886068523.

Adding to 7749 its sum of digits (27), we get a 5-th power (7776 = 6⁵).

Subtracting 7749 from its reverse (9477), we obtain a cube (1728 = 12³).

It can be divided in two parts, 77 and 49, that multiplied together give a palindrome (3773).

The spelling of 7749 in words is "seven thousand, seven hundred forty-nine".