66744678 has 64 divisors (see below), whose sum is σ = 179246592. Its totient is φ = 16001280.

The previous prime is 66744673. The next prime is 66744697. The reversal of 66744678 is 87644766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66744673) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 450 + ... + 11562.

It is an arithmetic number, because the mean of its divisors is an integer number (2800728).

Almost surely, 2^66744678 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66744678, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89623296).

66744678 is an abundant number, since it is smaller than the sum of its proper divisors (112501914).

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

66744678 is a wasteful number, since it uses less digits than its factorization.

66744678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11149.

The product of its digits is 1354752, while the sum is 48.

The square root of 66744678 is about 8169.7416115811. The cubic root of 66744678 is about 405.6382316159.

The spelling of 66744678 in words is "sixty-six million, seven hundred forty-four thousand, six hundred seventy-eight".