668505666740 has 12 divisors (see below), whose sum is σ = 1403861900196. Its totient is φ = 267402266688.

The previous prime is 668505666671. The next prime is 668505666761. The reversal of 668505666740 is 47666505866.

668505666740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 351786589456 + 316719077284 = 593116^2 + 562778^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 668505666740.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16712641649 + ... + 16712641688.

It is an arithmetic number, because the mean of its divisors is an integer number (116988491683).

Almost surely, 2^668505666740 is an apocalyptic number.

It is an amenable number.

668505666740 is an abundant number, since it is smaller than the sum of its proper divisors (735356233456).

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

668505666740 is a wasteful number, since it uses less digits than its factorization.

668505666740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33425283346 (or 33425283344 counting only the distinct ones).

The product of its (nonzero) digits is 43545600, while the sum is 59.

The spelling of 668505666740 in words is "six hundred sixty-eight billion, five hundred five million, six hundred sixty-six thousand, seven hundred forty".