66381100556 has 12 divisors (see below), whose sum is σ = 116169530568. Its totient is φ = 33189806112.

The previous prime is 66381100531. The next prime is 66381100567. The reversal of 66381100556 is 65500118366.

It is a super-2 number, since 2×66381100556² (a number of 22 digits) contains 22 as substring.

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, 47135 + ... + 367401.

It is an arithmetic number, because the mean of its divisors is an integer number (9680794214).

Almost surely, 2^66381100556 is an apocalyptic number.

It is an amenable number.

66381100556 is a deficient number, since it is larger than the sum of its proper divisors (49788430012).

66381100556 is a wasteful number, since it uses less digits than its factorization.

66381100556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372088 (or 372086 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 41.

The spelling of 66381100556 in words is "sixty-six billion, three hundred eighty-one million, one hundred thousand, five hundred fifty-six".