66355831181 has 4 divisors (see below), whose sum is σ = 66420192864. Its totient is φ = 66291469500.

The previous prime is 66355831177. The next prime is 66355831229. The reversal of 66355831181 is 18113855366.

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.

It is a cyclic number.

It is not a de Polignac number, because 66355831181 - 2² = 66355831177 is a prime.

It is a super-2 number, since 2×66355831181² (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 (66355831121) 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, 32179295 + ... + 32181356.

It is an arithmetic number, because the mean of its divisors is an integer number (16605048216).

Almost surely, 2^66355831181 is an apocalyptic number.

It is an amenable number.

66355831181 is a deficient number, since it is larger than the sum of its proper divisors (64361683).

66355831181 is a wasteful number, since it uses less digits than its factorization.

66355831181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64361682.

The product of its digits is 518400, while the sum is 47.

The spelling of 66355831181 in words is "sixty-six billion, three hundred fifty-five million, eight hundred thirty-one thousand, one hundred eighty-one".