7740 has 36 divisors (see below), whose sum is σ = 24024. Its totient is φ = 2016.

The previous prime is 7727. The next prime is 7741. The reversal of 7740 is 477.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 6 and base 10.

It is a zygodrome in base 2 and base 6.

It is a congruent number.

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

7740 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 159 + ... + 201.

2⁷⁷⁴⁰ is an apocalyptic number.

7740 is the 72-nd pentagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12012).

7740 is an abundant number, since it is smaller than the sum of its proper divisors (16284).

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

7740 is a wasteful number, since it uses less digits than its factorization.

7740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 18.

The square root of 7740 is about 87.9772697917. The cubic root of 7740 is about 19.7809427900.

It can be divided in two parts, 7 and 740, that added together give a palindrome (747).

The spelling of 7740 in words is "seven thousand, seven hundred forty", and thus it is an iban number.