665960761 has 2 divisors, whose sum is σ = 665960762. Its totient is φ = 665960760.

The previous prime is 665960747. The next prime is 665960777. The reversal of 665960761 is 167069566.

665960761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 447068736 + 218892025 = 21144^2 + 14795^2 .

It is a cyclic number.

It is not a de Polignac number, because 665960761 - 2¹³ = 665952569 is a prime.

It is a pancake number, because a pancake can be divided into 665960761 parts by 36495 straight cuts.

It is equal to p_34579729 and since 665960761 and 34579729 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (665960731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332980380 + 332980381.

It is an arithmetic number, because the mean of its divisors is an integer number (332980381).

Almost surely, 2^665960761 is an apocalyptic number.

It is an amenable number.

665960761 is a deficient number, since it is larger than the sum of its proper divisors (1).

665960761 is an equidigital number, since it uses as much as digits as its factorization.

665960761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 408240, while the sum is 46.

The square root of 665960761 is about 25806.2155497469. The cubic root of 665960761 is about 873.2720231452.

The spelling of 665960761 in words is "six hundred sixty-five million, nine hundred sixty thousand, seven hundred sixty-one".