66744299520 has 312 divisors, whose sum is σ = 238835405952. Its totient is φ = 17222860800.

The previous prime is 66744299491. The next prime is 66744299537. The reversal of 66744299520 is 2599244766.

66744299520 is a `hidden beast` number, since 6 + 6 + 74 + 42 + 9 + 9 + 520 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5708080 + ... + 5719760.

It is an arithmetic number, because the mean of its divisors is an integer number (765498096).

Almost surely, 2^66744299520 is an apocalyptic number.

66744299520 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 66744299520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119417702976).

66744299520 is an abundant number, since it is smaller than the sum of its proper divisors (172091106432).

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

66744299520 is a wasteful number, since it uses less digits than its factorization.

66744299520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11747 (or 11722 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 54.

The spelling of 66744299520 in words is "sixty-six billion, seven hundred forty-four million, two hundred ninety-nine thousand, five hundred twenty".