666849229640 has 32 divisors (see below), whose sum is σ = 1636811746560. Its totient is φ = 242490628800.

The previous prime is 666849229639. The next prime is 666849229691. The reversal of 666849229640 is 46922948666.

It is a super-2 number, since 2×666849229640² (a number of 24 digits) contains 22 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, 757782776 + ... + 757783655.

It is an arithmetic number, because the mean of its divisors is an integer number (51150367080).

Almost surely, 2^666849229640 is an apocalyptic number.

It is an amenable number.

666849229640 is an abundant number, since it is smaller than the sum of its proper divisors (969962516920).

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

666849229640 is a wasteful number, since it uses less digits than its factorization.

666849229640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515566453 (or 1515566449 counting only the distinct ones).

The product of its (nonzero) digits is 53747712, while the sum is 62.

The spelling of 666849229640 in words is "six hundred sixty-six billion, eight hundred forty-nine million, two hundred twenty-nine thousand, six hundred forty".