666722169792 has 448 divisors, whose sum is σ = 2322917376000. Its totient is φ = 183476772864.

The previous prime is 666722169791. The next prime is 666722169803. The reversal of 666722169792 is 297961227666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666722169791) 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 63 ways as a sum of consecutive naturals, for example, 160306209 + ... + 160310367.

Almost surely, 2^666722169792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666722169792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1161458688000).

666722169792 is an abundant number, since it is smaller than the sum of its proper divisors (1656195206208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666722169792 is a wasteful number, since it uses less digits than its factorization.

666722169792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4673 (or 4657 counting only the distinct ones).

The product of its digits is 41150592, while the sum is 63.

The spelling of 666722169792 in words is "six hundred sixty-six billion, seven hundred twenty-two million, one hundred sixty-nine thousand, seven hundred ninety-two".