666791817796 has 24 divisors (see below), whose sum is σ = 1259269643520. Its totient is φ = 307107573792.

The previous prime is 666791817793. The next prime is 666791817799. The reversal of 666791817796 is 697718197666.

It is an interprime number because it is at equal distance from previous prime (666791817793) and next prime (666791817799).

It is a super-2 number, since 2×666791817796² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666791817793) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13360186 + ... + 13410001.

It is an arithmetic number, because the mean of its divisors is an integer number (52469568480).

Almost surely, 2^666791817796 is an apocalyptic number.

It is an amenable number.

666791817796 is a deficient number, since it is larger than the sum of its proper divisors (592477825724).

666791817796 is a wasteful number, since it uses less digits than its factorization.

666791817796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26770683 (or 26770681 counting only the distinct ones).

The product of its digits is 288054144, while the sum is 73.

The spelling of 666791817796 in words is "six hundred sixty-six billion, seven hundred ninety-one million, eight hundred seventeen thousand, seven hundred ninety-six".