66681339960 has 64 divisors (see below), whose sum is σ = 203029776000. Its totient is φ = 17516290176.

The previous prime is 66681339941. The next prime is 66681339961. The reversal of 66681339960 is 6993318666.

It is a super-2 number, since 2×66681339960² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66681339960.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66681339961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4138810 + ... + 4154889.

It is an arithmetic number, because the mean of its divisors is an integer number (3172340250).

Almost surely, 2^66681339960 is an apocalyptic number.

66681339960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66681339960 is an abundant number, since it is smaller than the sum of its proper divisors (136348436040).

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

66681339960 is a wasteful number, since it uses less digits than its factorization.

66681339960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8293780 (or 8293776 counting only the distinct ones).

The product of its (nonzero) digits is 7558272, while the sum is 57.

The spelling of 66681339960 in words is "sixty-six billion, six hundred eighty-one million, three hundred thirty-nine thousand, nine hundred sixty".