66875840 has 56 divisors (see below), whose sum is σ = 160873440. Its totient is φ = 26477568.

The previous prime is 66875779. The next prime is 66875843. The reversal of 66875840 is 4857866.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 66875791 and 66875800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66875843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31946 + ... + 33974.

It is an arithmetic number, because the mean of its divisors is an integer number (2872740).

Almost surely, 2^66875840 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 66875840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80436720).

66875840 is an abundant number, since it is smaller than the sum of its proper divisors (93997600).

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

66875840 is a wasteful number, since it uses less digits than its factorization.

66875840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2149 (or 2139 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 44.

The square root of 66875840 is about 8177.7649758354. The cubic root of 66875840 is about 405.9037684357.

The spelling of 66875840 in words is "sixty-six million, eight hundred seventy-five thousand, eight hundred forty".