66349681920 has 864 divisors, whose sum is σ = 249785303040. Its totient is φ = 16228270080.

The previous prime is 66349681919. The next prime is 66349681927. The reversal of 66349681920 is 2918694366.

66349681920 is a `hidden beast` number, since 6 + 63 + 496 + 8 + 1 + 92 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66349681927) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 990293727 + ... + 990293793.

It is an arithmetic number, because the mean of its divisors is an integer number (289103360).

Almost surely, 2^66349681920 is an apocalyptic number.

66349681920 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 66349681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124892651520).

66349681920 is an abundant number, since it is smaller than the sum of its proper divisors (183435621120).

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

66349681920 is a wasteful number, since it uses less digits than its factorization.

66349681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 54.

The spelling of 66349681920 in words is "sixty-six billion, three hundred forty-nine million, six hundred eighty-one thousand, nine hundred twenty".