66651600511 has 4 divisors (see below), whose sum is σ = 70572282912. Its totient is φ = 62730918112.

The previous prime is 66651600481. The next prime is 66651600517. The reversal of 66651600511 is 11500615666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66651600511 - 2⁹ = 66651599999 is a prime.

It is a super-2 number, since 2×66651600511² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66651600517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1960341175 + ... + 1960341208.

It is an arithmetic number, because the mean of its divisors is an integer number (17643070728).

Almost surely, 2^66651600511 is an apocalyptic number.

66651600511 is a deficient number, since it is larger than the sum of its proper divisors (3920682401).

66651600511 is a wasteful number, since it uses less digits than its factorization.

66651600511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3920682400.

The product of its (nonzero) digits is 32400, while the sum is 37.

The spelling of 66651600511 in words is "sixty-six billion, six hundred fifty-one million, six hundred thousand, five hundred eleven".