66651138556 has 12 divisors (see below), whose sum is σ = 118840237992. Its totient is φ = 32696784848.

The previous prime is 66651138517. The next prime is 66651138577. The reversal of 66651138556 is 65583115666.

It is a super-2 number, since 2×66651138556² (a number of 22 digits) contains 22 as substring.

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, 157195870 + ... + 157196293.

It is an arithmetic number, because the mean of its divisors is an integer number (9903353166).

Almost surely, 2^66651138556 is an apocalyptic number.

It is an amenable number.

66651138556 is a deficient number, since it is larger than the sum of its proper divisors (52189099436).

66651138556 is a wasteful number, since it uses less digits than its factorization.

66651138556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314392220 (or 314392218 counting only the distinct ones).

The product of its digits is 3888000, while the sum is 52.

The spelling of 66651138556 in words is "sixty-six billion, six hundred fifty-one million, one hundred thirty-eight thousand, five hundred fifty-six".