66511656 has 24 divisors (see below), whose sum is σ = 180135930. Its totient is φ = 22170528.

The previous prime is 66511651. The next prime is 66511727. The reversal of 66511656 is 65611566.

It can be written as a sum of positive squares in only one way, i.e., 54022500 + 12489156 = 7350^2 + 3534^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (36) 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 (36).

It is a self number, because there is not a number n which added to its sum of digits gives 66511656.

It is not an unprimeable number, because it can be changed into a prime (66511651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 461815 + ... + 461958.

Almost surely, 2^66511656 is an apocalyptic number.

It is an amenable number.

66511656 is an abundant number, since it is smaller than the sum of its proper divisors (113624274).

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

66511656 is a wasteful number, since it uses less digits than its factorization.

66511656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923785 (or 923778 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 66511656 is about 8155.4678590501. The cubic root of 66511656 is about 405.1656204194.

It can be divided in two parts, 665 and 11656, that added together give a palindrome (12321).

The spelling of 66511656 in words is "sixty-six million, five hundred eleven thousand, six hundred fifty-six".