764640 has 120 divisors (see below), whose sum is σ = 2744280. Its totient is φ = 200448.

The previous prime is 764629. The next prime is 764657. The reversal of 764640 is 46467.

764640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is an unprimeable number.

764640 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 19 ways as a sum of consecutive naturals, for example, 12931 + ... + 12989.

It is an arithmetic number, because the mean of its divisors is an integer number (22869).

2⁷⁶⁴⁶⁴⁰ 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 764640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1372140).

764640 is an abundant number, since it is smaller than the sum of its proper divisors (1979640).

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

764640 is a wasteful number, since it uses less digits than its factorization.

764640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 764640 is about 874.4369617074. The cubic root of 764640 is about 91.4433941741.

The spelling of 764640 in words is "seven hundred sixty-four thousand, six hundred forty".