66255611761 has 4 divisors (see below), whose sum is σ = 66373295472. Its totient is φ = 66137928052.

The previous prime is 66255611717. The next prime is 66255611819. The reversal of 66255611761 is 16711655266.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16711655266 = 2 ⋅8355827633.

It is a cyclic number.

It is not a de Polignac number, because 66255611761 - 2²⁹ = 65718740849 is a prime.

It is a super-2 number, since 2×66255611761² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66255611701) 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, 58841011 + ... + 58842136.

It is an arithmetic number, because the mean of its divisors is an integer number (16593323868).

Almost surely, 2^66255611761 is an apocalyptic number.

It is an amenable number.

66255611761 is a deficient number, since it is larger than the sum of its proper divisors (117683711).

66255611761 is a wasteful number, since it uses less digits than its factorization.

66255611761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117683710.

The product of its digits is 453600, while the sum is 46.

The spelling of 66255611761 in words is "sixty-six billion, two hundred fifty-five million, six hundred eleven thousand, seven hundred sixty-one".