668140081540 has 24 divisors (see below), whose sum is σ = 1403469587520. Its totient is φ = 267184524768.

The previous prime is 668140081537. The next prime is 668140081559. The reversal of 668140081540 is 45180041866.

It is a super-2 number, since 2×668140081540² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4392592 + ... + 4542151.

It is an arithmetic number, because the mean of its divisors is an integer number (58477899480).

Almost surely, 2^668140081540 is an apocalyptic number.

It is an amenable number.

668140081540 is an abundant number, since it is smaller than the sum of its proper divisors (735329505980).

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

668140081540 is a wasteful number, since it uses less digits than its factorization.

668140081540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8938491 (or 8938489 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 668140081540 in words is "six hundred sixty-eight billion, one hundred forty million, eighty-one thousand, five hundred forty".