66439353440 has 96 divisors (see below), whose sum is σ = 159497281440.
Its totient is φ = 26150068224.
The previous prime is 66439353439. The next prime is 66439353521. The reversal of 66439353440 is 4435393466.
It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2499902 + ... + 2526338.
It is an arithmetic number, because the mean of its divisors is an integer number (1661430015).
Almost surely, 266439353440 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 66439353440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79748640720).
66439353440 is an abundant number, since it is smaller than the sum of its proper divisors (93057928000).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
66439353440 is a wasteful number, since it uses less digits than its factorization.
66439353440 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 26704 (or 26696 counting only the distinct ones).
The product of its (nonzero) digits is 2799360, while the sum is 47.
The spelling of 66439353440 in words is "sixty-six billion, four hundred thirty-nine million, three hundred fifty-three thousand, four hundred forty".