66515897448 has 768 divisors, whose sum is σ = 250925875200. Its totient is φ = 15454333440.

The previous prime is 66515897447. The next prime is 66515897453. The reversal of 66515897448 is 84479851566.

66515897448 is a `hidden beast` number, since 6 + 6 + 5 + 1 + 589 + 7 + 4 + 48 = 666.

It is a super-2 number, since 2×66515897448² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (66515897447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 523747161 + ... + 523747287.

It is an arithmetic number, because the mean of its divisors is an integer number (326726400).

Almost surely, 2^66515897448 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 66515897448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125462937600).

66515897448 is an abundant number, since it is smaller than the sum of its proper divisors (184409977752).

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

66515897448 is a wasteful number, since it uses less digits than its factorization.

66515897448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 206 counting only the distinct ones).

The product of its digits is 58060800, while the sum is 63.

The spelling of 66515897448 in words is "sixty-six billion, five hundred fifteen million, eight hundred ninety-seven thousand, four hundred forty-eight".