66186478331 has 4 divisors (see below), whose sum is σ = 66552149664. Its totient is φ = 65820807000.

The previous prime is 66186478313. The next prime is 66186478373. The reversal of 66186478331 is 13387468166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13387468166 = 2 ⋅6693734083.

It is a cyclic number.

It is not a de Polignac number, because 66186478331 - 2³⁴ = 49006609147 is a prime.

It is a super-2 number, since 2×66186478331² (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 (66186478031) 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 3 ways as a sum of consecutive naturals, for example, 182835395 + ... + 182835756.

It is an arithmetic number, because the mean of its divisors is an integer number (16638037416).

Almost surely, 2^66186478331 is an apocalyptic number.

66186478331 is a deficient number, since it is larger than the sum of its proper divisors (365671333).

66186478331 is a wasteful number, since it uses less digits than its factorization.

66186478331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365671332.

The product of its digits is 3483648, while the sum is 53.

The spelling of 66186478331 in words is "sixty-six billion, one hundred eighty-six million, four hundred seventy-eight thousand, three hundred thirty-one".