66551551761 has 8 divisors (see below), whose sum is σ = 90623389824. Its totient is φ = 43423707440.

The previous prime is 66551551751. The next prime is 66551551763. The reversal of 66551551761 is 16715515566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66551551761 - 2¹⁴ = 66551535377 is a prime.

It is a super-2 number, since 2×66551551761² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66551551761.

It is not an unprimeable number, because it can be changed into a prime (66551551763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235998270 + ... + 235998551.

It is an arithmetic number, because the mean of its divisors is an integer number (11327923728).

Almost surely, 2^66551551761 is an apocalyptic number.

It is an amenable number.

66551551761 is a deficient number, since it is larger than the sum of its proper divisors (24071838063).

66551551761 is a wasteful number, since it uses less digits than its factorization.

66551551761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471996871.

The product of its digits is 945000, while the sum is 48.

The spelling of 66551551761 in words is "sixty-six billion, five hundred fifty-one million, five hundred fifty-one thousand, seven hundred sixty-one".