67721761660 has 96 divisors (see below), whose sum is σ = 169913318400. Its totient is φ = 22168194048.

The previous prime is 67721761649. The next prime is 67721761661. The reversal of 67721761660 is 6616712776.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67721761661) 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 31 ways as a sum of consecutive naturals, for example, 1742116 + ... + 1780564.

It is an arithmetic number, because the mean of its divisors is an integer number (1769930400).

Almost surely, 2^67721761660 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 67721761660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84956659200).

67721761660 is an abundant number, since it is smaller than the sum of its proper divisors (102191556740).

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

67721761660 is a wasteful number, since it uses less digits than its factorization.

67721761660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39035 (or 39033 counting only the distinct ones).

The product of its (nonzero) digits is 889056, while the sum is 49.

The spelling of 67721761660 in words is "sixty-seven billion, seven hundred twenty-one million, seven hundred sixty-one thousand, six hundred sixty".