66013666388 has 6 divisors (see below), whose sum is σ = 115523916186. Its totient is φ = 33006833192.

The previous prime is 66013666387. The next prime is 66013666427. The reversal of 66013666388 is 88366631066.

It can be written as a sum of positive squares in only one way, i.e., 55784771344 + 10228895044 = 236188^2 + 101138^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66013666387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8251708295 + ... + 8251708302.

It is an arithmetic number, because the mean of its divisors is an integer number (19253986031).

Almost surely, 2^66013666388 is an apocalyptic number.

It is an amenable number.

66013666388 is a deficient number, since it is larger than the sum of its proper divisors (49510249798).

66013666388 is a wasteful number, since it uses less digits than its factorization.

66013666388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16503416601 (or 16503416599 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 53.

The spelling of 66013666388 in words is "sixty-six billion, thirteen million, six hundred sixty-six thousand, three hundred eighty-eight".