66991003473528 has 192 divisors, whose sum is σ = 191186049600000. Its totient is φ = 21149248184064.

The previous prime is 66991003473509. The next prime is 66991003473557. The reversal of 66991003473528 is 82537430019966.

66991003473528 is a `hidden beast` number, since 6 + 6 + 9 + 9 + 1 + 0 + 0 + 34 + 73 + 528 = 666.

It is a super-2 number, since 2×66991003473528² (a number of 28 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1540036723 + ... + 1540080221.

It is an arithmetic number, because the mean of its divisors is an integer number (995760675000).

It is a 2-persistent number, because it is pandigital, and so is 2⋅66991003473528 = 133982006947056, but 3⋅66991003473528 = 200973010420584 is not.

Almost surely, 2^{66991003473528} 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 66991003473528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95593024800000).

66991003473528 is an abundant number, since it is smaller than the sum of its proper divisors (124195046126472).

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

66991003473528 is a wasteful number, since it uses less digits than its factorization.

66991003473528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52666 (or 52659 counting only the distinct ones).

The product of its (nonzero) digits is 58786560, while the sum is 63.

The spelling of 66991003473528 in words is "sixty-six trillion, nine hundred ninety-one billion, three million, four hundred seventy-three thousand, five hundred twenty-eight".