66139950996 has 72 divisors (see below), whose sum is σ = 191386191360. Its totient is φ = 18865953216.

The previous prime is 66139950977. The next prime is 66139950997. The reversal of 66139950996 is 69905993166.

66139950996 is a `hidden beast` number, since 6 + 6 + 1 + 39 + 9 + 509 + 96 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66139950997) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63231 + ... + 369158.

Almost surely, 2^66139950996 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 66139950996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95693095680).

66139950996 is an abundant number, since it is smaller than the sum of its proper divisors (125246240364).

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

66139950996 is a wasteful number, since it uses less digits than its factorization.

66139950996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433013 (or 433008 counting only the distinct ones).

The product of its (nonzero) digits is 21257640, while the sum is 63.

The spelling of 66139950996 in words is "sixty-six billion, one hundred thirty-nine million, nine hundred fifty thousand, nine hundred ninety-six".