664818085866 has 48 divisors (see below), whose sum is σ = 1483314471072. Its totient is φ = 198453145440.

The previous prime is 664818085843. The next prime is 664818085889. The reversal of 664818085866 is 668580818466.

It is an interprime number because it is at equal distance from previous prime (664818085843) and next prime (664818085889).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a junction number, because it is equal to n+sod(n) for n = 664818085797 and 664818085806.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6785145 + ... + 6882428.

It is an arithmetic number, because the mean of its divisors is an integer number (30902384814).

Almost surely, 2^664818085866 is an apocalyptic number.

664818085866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

664818085866 is an abundant number, since it is smaller than the sum of its proper divisors (818496385206).

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

664818085866 is a wasteful number, since it uses less digits than its factorization.

664818085866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13667667 (or 13667656 counting only the distinct ones).

The product of its (nonzero) digits is 106168320, while the sum is 66.

The spelling of 664818085866 in words is "six hundred sixty-four billion, eight hundred eighteen million, eighty-five thousand, eight hundred sixty-six".