66072464640 has 1440 divisors, whose sum is σ = 299163110400. Its totient is φ = 13552386048.

The previous prime is 66072464609. The next prime is 66072464659. The reversal of 66072464640 is 4646427066.

66072464640 is a `hidden beast` number, since 6 + 60 + 72 + 464 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

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 159 ways as a sum of consecutive naturals, for example, 443439286 + ... + 443439434.

It is an arithmetic number, because the mean of its divisors is an integer number (207752160).

Almost surely, 2^66072464640 is an apocalyptic number.

66072464640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66072464640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149581555200).

66072464640 is an abundant number, since it is smaller than the sum of its proper divisors (233090645760).

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

66072464640 is a wasteful number, since it uses less digits than its factorization.

66072464640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 45.

The spelling of 66072464640 in words is "sixty-six billion, seventy-two million, four hundred sixty-four thousand, six hundred forty".