66644464346880 has 1728 divisors, whose sum is σ = 268214315765760. Its totient is φ = 14008909824000.

The previous prime is 66644464346879. The next prime is 66644464346903. The reversal of 66644464346880 is 8864346444666.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 34159129905 + ... + 34159131855.

It is an arithmetic number, because the mean of its divisors is an integer number (155216617920).

Almost surely, 2^{66644464346880} is an apocalyptic number.

66644464346880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66644464346880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134107157882880).

66644464346880 is an abundant number, since it is smaller than the sum of its proper divisors (201569851418880).

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

66644464346880 is a wasteful number, since it uses less digits than its factorization.

66644464346880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2246 (or 2225 counting only the distinct ones).

The product of its (nonzero) digits is 1528823808, while the sum is 69.

The spelling of 66644464346880 in words is "sixty-six trillion, six hundred forty-four billion, four hundred sixty-four million, three hundred forty-six thousand, eight hundred eighty".