764440 has 32 divisors (see below), whose sum is σ = 1782000. Its totient is φ = 294784.

The previous prime is 764431. The next prime is 764447. The reversal of 764440 is 44467.

It is a happy number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (764447) 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, 831 + ... + 1489.

2⁷⁶⁴⁴⁴⁰ 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 764440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (891000).

764440 is an abundant number, since it is smaller than the sum of its proper divisors (1017560).

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

764440 is a wasteful number, since it uses less digits than its factorization.

764440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699 (or 695 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 764440 is about 874.3225949271. The cubic root of 764440 is about 91.4354208038.

The spelling of 764440 in words is "seven hundred sixty-four thousand, four hundred forty".