665872056280666 has 16 divisors (see below), whose sum is σ = 1057561991190144. Its totient is φ = 313351410700224.

The previous prime is 665872056280657. The next prime is 665872056280729. The reversal of 665872056280666 is 666082650278566.

It is a super-3 number, since 3×665872056280666³ (a number of 45 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117442981 + ... + 122982103.

It is an arithmetic number, because the mean of its divisors is an integer number (66097624449384).

Almost surely, 2^{665872056280666} is an apocalyptic number.

665872056280666 is a deficient number, since it is larger than the sum of its proper divisors (391689934909478).

665872056280666 is a wasteful number, since it uses less digits than its factorization.

665872056280666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9074805.

The product of its (nonzero) digits is 2090188800, while the sum is 73.

The spelling of 665872056280666 in words is "six hundred sixty-five trillion, eight hundred seventy-two billion, fifty-six million, two hundred eighty thousand, six hundred sixty-six".