665745366 has 128 divisors (see below), whose sum is σ = 1635734016. Its totient is φ = 177914880.

The previous prime is 665745343. The next prime is 665745383. The reversal of 665745366 is 663547566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2126826 + ... + 2127138.

It is an arithmetic number, because the mean of its divisors is an integer number (12779172).

Almost surely, 2^665745366 is an apocalyptic number.

665745366 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 665745366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (817867008).

665745366 is an abundant number, since it is smaller than the sum of its proper divisors (969988650).

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

665745366 is a wasteful number, since it uses less digits than its factorization.

665745366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446.

The product of its digits is 2721600, while the sum is 48.

The square root of 665745366 is about 25802.0418959430. The cubic root of 665745366 is about 873.1778640889.

It can be divided in two parts, 665 and 745366, that added together give a triangular number (746031 = T₁₂₂₁).

The spelling of 665745366 in words is "six hundred sixty-five million, seven hundred forty-five thousand, three hundred sixty-six".