66999629720 has 16 divisors (see below), whose sum is σ = 150749166960. Its totient is φ = 26799851872.

The previous prime is 66999629663. The next prime is 66999629729. The reversal of 66999629720 is 2792699966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66999629729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 837495332 + ... + 837495411.

It is an arithmetic number, because the mean of its divisors is an integer number (9421822935).

Almost surely, 2^66999629720 is an apocalyptic number.

It is an amenable number.

66999629720 is an abundant number, since it is smaller than the sum of its proper divisors (83749537240).

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

66999629720 is a wasteful number, since it uses less digits than its factorization.

66999629720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1674990754 (or 1674990750 counting only the distinct ones).

The product of its (nonzero) digits is 39680928, while the sum is 65.

The spelling of 66999629720 in words is "sixty-six billion, nine hundred ninety-nine million, six hundred twenty-nine thousand, seven hundred twenty".