66731505696 has 576 divisors, whose sum is σ = 220134620160. Its totient is φ = 19627868160.

The previous prime is 66731505641. The next prime is 66731505703. The reversal of 66731505696 is 69650513766.

66731505696 is a `hidden beast` number, since 6 + 6 + 73 + 1 + 5 + 0 + 569 + 6 = 666.

It is a super-3 number, since 3×66731505696³ (a number of 33 digits) contains 333 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 286401196 + ... + 286401428.

It is an arithmetic number, because the mean of its divisors is an integer number (382178160).

Almost surely, 2^66731505696 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 66731505696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110067310080).

66731505696 is an abundant number, since it is smaller than the sum of its proper divisors (153403114464).

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

66731505696 is a wasteful number, since it uses less digits than its factorization.

66731505696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 6123600, while the sum is 54.

The spelling of 66731505696 in words is "sixty-six billion, seven hundred thirty-one million, five hundred five thousand, six hundred ninety-six".