665440166986 has 32 divisors (see below), whose sum is σ = 1173301752960. Its totient is φ = 277074426816.

The previous prime is 665440166971. The next prime is 665440167019. The reversal of 665440166986 is 689661044566.

It is a happy number.

665440166986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 586641 + ... + 1294228.

It is an arithmetic number, because the mean of its divisors is an integer number (36665679780).

Almost surely, 2^665440166986 is an apocalyptic number.

665440166986 is a deficient number, since it is larger than the sum of its proper divisors (507861585974).

665440166986 is a wasteful number, since it uses less digits than its factorization.

665440166986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1881598.

The product of its (nonzero) digits is 44789760, while the sum is 61.

The spelling of 665440166986 in words is "six hundred sixty-five billion, four hundred forty million, one hundred sixty-six thousand, nine hundred eighty-six".