66644266231 has 4 divisors (see below), whose sum is σ = 66694489312. Its totient is φ = 66594043152.

The previous prime is 66644266229. The next prime is 66644266243. The reversal of 66644266231 is 13266244666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13266244666 = 2 ⋅6633122333.

It is a cyclic number.

It is not a de Polignac number, because 66644266231 - 2¹ = 66644266229 is a prime.

It is a super-2 number, since 2×66644266231² (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 (66644266531) 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, 25109550 + ... + 25112203.

It is an arithmetic number, because the mean of its divisors is an integer number (16673622328).

Almost surely, 2^66644266231 is an apocalyptic number.

66644266231 is a deficient number, since it is larger than the sum of its proper divisors (50223081).

66644266231 is a wasteful number, since it uses less digits than its factorization.

66644266231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50223080.

The product of its digits is 1492992, while the sum is 46.

The spelling of 66644266231 in words is "sixty-six billion, six hundred forty-four million, two hundred sixty-six thousand, two hundred thirty-one".