7764640 has 48 divisors (see below), whose sum is σ = 19760328. Its totient is φ = 2866176.

The previous prime is 7764613. The next prime is 7764641. The reversal of 7764640 is 464677.

It can be written as a sum of positive squares in 4 ways, for example, as 5035536 + 2729104 = 2244^2 + 1652^2 .

It is a junction number, because it is equal to n+sod(n) for n = 7764596 and 7764605.

It is not an unprimeable number, because it can be changed into a prime (7764641) 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, 214 + ... + 3946.

Almost surely, 2^7764640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7764640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9880164).

7764640 is an abundant number, since it is smaller than the sum of its proper divisors (11995688).

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

7764640 is a wasteful number, since it uses less digits than its factorization.

7764640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3761 (or 3753 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 34.

The square root of 7764640 is about 2786.5103624426. The cubic root of 7764640 is about 198.0191118511.

The spelling of 7764640 in words is "seven million, seven hundred sixty-four thousand, six hundred forty".