66906144321 has 4 divisors (see below), whose sum is σ = 89208192432. Its totient is φ = 44604096212.

The previous prime is 66906144287. The next prime is 66906144337. The reversal of 66906144321 is 12344160966.

It is a happy number.

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 66906144321 - 2¹¹ = 66906142273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66906144391) 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, 11151024051 + ... + 11151024056.

It is an arithmetic number, because the mean of its divisors is an integer number (22302048108).

Almost surely, 2^66906144321 is an apocalyptic number.

It is an amenable number.

66906144321 is a deficient number, since it is larger than the sum of its proper divisors (22302048111).

66906144321 is a wasteful number, since it uses less digits than its factorization.

66906144321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22302048110.

The product of its (nonzero) digits is 186624, while the sum is 42.

The spelling of 66906144321 in words is "sixty-six billion, nine hundred six million, one hundred forty-four thousand, three hundred twenty-one".