667738554642 has 12 divisors (see below), whose sum is σ = 1446766868430. Its totient is φ = 222579518208.

The previous prime is 667738554599. The next prime is 667738554643. The reversal of 667738554642 is 246455837766.

It is a happy number.

667738554642 is a `hidden beast` number, since 6 + 6 + 7 + 7 + 3 + 85 + 546 + 4 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 574701964281 + 93036590361 = 758091^2 + 305019^2 .

It is a super-3 number, since 3×667738554642³ (a number of 36 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 667738554642.

It is not an unprimeable number, because it can be changed into a prime (667738554643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18548293167 + ... + 18548293202.

Almost surely, 2^667738554642 is an apocalyptic number.

667738554642 is an abundant number, since it is smaller than the sum of its proper divisors (779028313788).

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

667738554642 is a wasteful number, since it uses less digits than its factorization.

667738554642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37096586377 (or 37096586374 counting only the distinct ones).

The product of its digits is 203212800, while the sum is 63.

The spelling of 667738554642 in words is "six hundred sixty-seven billion, seven hundred thirty-eight million, five hundred fifty-four thousand, six hundred forty-two".