66666012031 has 4 divisors (see below), whose sum is σ = 66688155864. Its totient is φ = 66643868200.

The previous prime is 66666011963. The next prime is 66666012037. The reversal of 66666012031 is 13021066666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66666012031 - 2²⁵ = 66632457599 is a prime.

It is a super-2 number, since 2×66666012031² (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 (66666012037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11067400 + ... + 11073421.

It is an arithmetic number, because the mean of its divisors is an integer number (16672038966).

Almost surely, 2^66666012031 is an apocalyptic number.

66666012031 is a deficient number, since it is larger than the sum of its proper divisors (22143833).

66666012031 is a wasteful number, since it uses less digits than its factorization.

66666012031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22143832.

The product of its (nonzero) digits is 46656, while the sum is 37.

Adding to 66666012031 its reverse (13021066666), we get a palindrome (79687078697).

The spelling of 66666012031 in words is "sixty-six billion, six hundred sixty-six million, twelve thousand, thirty-one".