66878910 has 96 divisors (see below), whose sum is σ = 201277440. Its totient is φ = 15090624.

The previous prime is 66878909. The next prime is 66878921. The reversal of 66878910 is 1987866.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 51651 + ... + 52929.

It is an arithmetic number, because the mean of its divisors is an integer number (2096640).

Almost surely, 2^66878910 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66878910, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100638720).

66878910 is an abundant number, since it is smaller than the sum of its proper divisors (134398530).

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

66878910 is a wasteful number, since it uses less digits than its factorization.

66878910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1382 (or 1379 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 66878910 is about 8177.9526777794. The cubic root of 66878910 is about 405.9099794754.

The spelling of 66878910 in words is "sixty-six million, eight hundred seventy-eight thousand, nine hundred ten".