66696981120 has 1920 divisors, whose sum is σ = 315165312000. Its totient is φ = 13412044800.

The previous prime is 66696981103. The next prime is 66696981121. The reversal of 66696981120 is 2118969666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66696981121) by changing a digit.

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 239 ways as a sum of consecutive naturals, for example, 2151515505 + ... + 2151515535.

It is an arithmetic number, because the mean of its divisors is an integer number (164148600).

Almost surely, 2^66696981120 is an apocalyptic number.

66696981120 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 66696981120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157582656000).

66696981120 is an abundant number, since it is smaller than the sum of its proper divisors (248468330880).

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

66696981120 is a wasteful number, since it uses less digits than its factorization.

66696981120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The spelling of 66696981120 in words is "sixty-six billion, six hundred ninety-six million, nine hundred eighty-one thousand, one hundred twenty".