66826971456 has 336 divisors, whose sum is σ = 217857994560. Its totient is φ = 17975623680.

The previous prime is 66826971439. The next prime is 66826971469. The reversal of 66826971456 is 65417962866.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×66826971456² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 66826971456.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30923016 + ... + 30925176.

Almost surely, 2^66826971456 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 66826971456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108928997280).

66826971456 is an abundant number, since it is smaller than the sum of its proper divisors (151031023104).

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

66826971456 is a wasteful number, since it uses less digits than its factorization.

66826971456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2382 (or 2365 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 60.

The spelling of 66826971456 in words is "sixty-six billion, eight hundred twenty-six million, nine hundred seventy-one thousand, four hundred fifty-six".