66535811556 has 96 divisors (see below), whose sum is σ = 172881838080. Its totient is φ = 19809022464.

The previous prime is 66535811519. The next prime is 66535811603. The reversal of 66535811556 is 65511853566.

It is a super-2 number, since 2×66535811556² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a junction number, because it is equal to n+sod(n) for n = 66535811499 and 66535811508.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 540055 + ... + 651713.

It is an arithmetic number, because the mean of its divisors is an integer number (1800852480).

Almost surely, 2^66535811556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66535811556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86440919040).

66535811556 is an abundant number, since it is smaller than the sum of its proper divisors (106346026524).

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

66535811556 is a wasteful number, since it uses less digits than its factorization.

66535811556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111833 (or 111831 counting only the distinct ones).

The product of its digits is 3240000, while the sum is 51.

The spelling of 66535811556 in words is "sixty-six billion, five hundred thirty-five million, eight hundred eleven thousand, five hundred fifty-six".