764865666 has 120 divisors (see below), whose sum is σ = 1881595980. Its totient is φ = 232217280.

The previous prime is 764865617. The next prime is 764865671. The reversal of 764865666 is 666568467.

764865666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 762919641 + 1946025 = 27621^2 + 1395^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 24673071 + ... + 24673101.

Almost surely, 2^764865666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 764865666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (940797990).

764865666 is an abundant number, since it is smaller than the sum of its proper divisors (1116730314).

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

764865666 is an equidigital number, since it uses as much as digits as its factorization.

764865666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 53 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 54.

The square root of 764865666 is about 27656.2048372513. The cubic root of 764865666 is about 914.5238909779.

The spelling of 764865666 in words is "seven hundred sixty-four million, eight hundred sixty-five thousand, six hundred sixty-six".