665746705 has 16 divisors (see below), whose sum is σ = 866641104. Its totient is φ = 488033280.

The previous prime is 665746703. The next prime is 665746721. The reversal of 665746705 is 507647566.

It can be written as a sum of positive squares in 8 ways, for example, as 69605649 + 596141056 = 8343^2 + 24416^2 .

It is not a de Polignac number, because 665746705 - 2¹ = 665746703 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665746703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28476 + ... + 46285.

It is an arithmetic number, because the mean of its divisors is an integer number (54165069).

Almost surely, 2^665746705 is an apocalyptic number.

665746705 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

665746705 is a deficient number, since it is larger than the sum of its proper divisors (200894399).

665746705 is a wasteful number, since it uses less digits than its factorization.

665746705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74916.

The product of its (nonzero) digits is 1058400, while the sum is 46.

The square root of 665746705 is about 25802.0678434888. The cubic root of 665746705 is about 873.1784494901.

The spelling of 665746705 in words is "six hundred sixty-five million, seven hundred forty-six thousand, seven hundred five".