666684761858 has 32 divisors (see below), whose sum is σ = 1012185195120. Its totient is φ = 329309245440.

The previous prime is 666684761807. The next prime is 666684761921. The reversal of 666684761858 is 858167486666.

It can be written as a sum of positive squares in 8 ways, for example, as 336408120049 + 330276641809 = 580007^2 + 574697^2 .

It is a super-3 number, since 3×666684761858³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 666684761791 and 666684761800.

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, 129375410 + ... + 129380562.

Almost surely, 2^666684761858 is an apocalyptic number.

666684761858 is a deficient number, since it is larger than the sum of its proper divisors (345500433262).

666684761858 is a wasteful number, since it uses less digits than its factorization.

666684761858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6902.

The product of its digits is 557383680, while the sum is 71.

The spelling of 666684761858 in words is "six hundred sixty-six billion, six hundred eighty-four million, seven hundred sixty-one thousand, eight hundred fifty-eight".