66551666515761 has 8 divisors (see below), whose sum is σ = 101412063262144. Its totient is φ = 38029523723280.

The previous prime is 66551666515709. The next prime is 66551666515783. The reversal of 66551666515761 is 16751566615566.

It is a happy number.

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

It is not a de Polignac number, because 66551666515761 - 2¹⁰ = 66551666514737 is a prime.

It is a super-2 number, since 2×66551666515761² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66551666515692 and 66551666515701.

It is not an unprimeable number, because it can be changed into a prime (66551666515561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1584563488450 + ... + 1584563488491.

It is an arithmetic number, because the mean of its divisors is an integer number (12676507907768).

Almost surely, 2^{66551666515761} is an apocalyptic number.

It is an amenable number.

66551666515761 is a deficient number, since it is larger than the sum of its proper divisors (34860396746383).

66551666515761 is a wasteful number, since it uses less digits than its factorization.

66551666515761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3169126976951.

The product of its digits is 204120000, while the sum is 66.

The spelling of 66551666515761 in words is "sixty-six trillion, five hundred fifty-one billion, six hundred sixty-six million, five hundred fifteen thousand, seven hundred sixty-one".