66485279520 has 360 divisors, whose sum is σ = 257913563292. Its totient is φ = 16117263360.

The previous prime is 66485279519. The next prime is 66485279527. The reversal of 66485279520 is 2597258466.

66485279520 is a `hidden beast` number, since 6 + 6 + 4 + 8 + 527 + 95 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 66458777616 + 26501904 = 257796^2 + 5148^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (66485279527) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1546962 + ... + 1589358.

Almost surely, 2^66485279520 is an apocalyptic number.

66485279520 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 66485279520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128956781646).

66485279520 is an abundant number, since it is smaller than the sum of its proper divisors (191428283772).

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

66485279520 is a wasteful number, since it uses less digits than its factorization.

66485279520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42446 (or 42418 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 54.

The spelling of 66485279520 in words is "sixty-six billion, four hundred eighty-five million, two hundred seventy-nine thousand, five hundred twenty".