666755369550 has 72 divisors (see below), whose sum is σ = 1792174158840. Its totient is φ = 177719572800.

The previous prime is 666755369477. The next prime is 666755369557. The reversal of 666755369550 is 55963557666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666755369557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 640560 + ... + 1320540.

Almost surely, 2^666755369550 is an apocalyptic number.

666755369550 is an abundant number, since it is smaller than the sum of its proper divisors (1125418789290).

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

666755369550 is a wasteful number, since it uses less digits than its factorization.

666755369550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682178 (or 682170 counting only the distinct ones).

The product of its (nonzero) digits is 153090000, while the sum is 63.

The spelling of 666755369550 in words is "six hundred sixty-six billion, seven hundred fifty-five million, three hundred sixty-nine thousand, five hundred fifty".