66923840 has 56 divisors (see below), whose sum is σ = 160141920. Its totient is φ = 26638848.

The previous prime is 66923827. The next prime is 66923869. The reversal of 66923840 is 4832966.

It is a junction number, because it is equal to n+sod(n) for n = 66923794 and 66923803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90191 + ... + 90929.

Almost surely, 2^66923840 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 66923840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80070960).

66923840 is an abundant number, since it is smaller than the sum of its proper divisors (93218080).

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

66923840 is a wasteful number, since it uses less digits than its factorization.

66923840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1039 (or 1029 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 66923840 is about 8180.6992366179. The cubic root of 66923840 is about 406.0008574161. Note that the first 3 decimals are identical.

The spelling of 66923840 in words is "sixty-six million, nine hundred twenty-three thousand, eight hundred forty".