764640816 has 80 divisors (see below), whose sum is σ = 2078387808. Its totient is φ = 241920000.

The previous prime is 764640803. The next prime is 764640817. The reversal of 764640816 is 618046467.

It is not an unprimeable number, because it can be changed into a prime (764640817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67566 + ... + 78066.

Almost surely, 2^764640816 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 764640816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1039193904).

764640816 is an abundant number, since it is smaller than the sum of its proper divisors (1313746992).

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

764640816 is a wasteful number, since it uses less digits than its factorization.

764640816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10590 (or 10584 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 42.

The square root of 764640816 is about 27652.1394470663. The cubic root of 764640816 is about 914.4342670263.

The spelling of 764640816 in words is "seven hundred sixty-four million, six hundred forty thousand, eight hundred sixteen".