66846215520 has 360 divisors, whose sum is σ = 274430195424. Its totient is φ = 15278989824.

The previous prime is 66846215509. The next prime is 66846215521. The reversal of 66846215520 is 2551264866.

66846215520 is a `hidden beast` number, since 6 + 68 + 4 + 62 + 1 + 5 + 520 = 666.

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 (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66846215521) 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, 582409 + ... + 687671.

Almost surely, 2^66846215520 is an apocalyptic number.

66846215520 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 66846215520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137215097712).

66846215520 is an abundant number, since it is smaller than the sum of its proper divisors (207583979904).

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

66846215520 is a wasteful number, since it uses less digits than its factorization.

66846215520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105304 (or 105280 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 66846215520 in words is "sixty-six billion, eight hundred forty-six million, two hundred fifteen thousand, five hundred twenty".