66681792 has 140 divisors (see below), whose sum is σ = 208376520. Its totient is φ = 21026304.

The previous prime is 66681779. The next prime is 66681793. The reversal of 66681792 is 29718666.

It is a super-2 number, since 2×66681792² = 8892922768662528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66681793) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 98158 + ... + 98834.

Almost surely, 2^66681792 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 66681792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104188260).

66681792 is an abundant number, since it is smaller than the sum of its proper divisors (141694728).

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

66681792 is a wasteful number, since it uses less digits than its factorization.

66681792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720 (or 701 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 66681792 is about 8165.8919904686. The cubic root of 66681792 is about 405.5107958303.

The spelling of 66681792 in words is "sixty-six million, six hundred eighty-one thousand, seven hundred ninety-two".