66999974631552 has 192 divisors, whose sum is σ = 193143150977400. Its totient is φ = 22293541552128.

The previous prime is 66999974631547. The next prime is 66999974631587. The reversal of 66999974631552 is 25513647999966.

66999974631552 is a `hidden beast` number, since 6 + 6 + 9 + 9 + 9 + 97 + 463 + 15 + 52 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 56267641382976 + 10732333248576 = 7501176^2 + 3276024^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×66999974631552² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1546857448 + ... + 1546900760.

Almost surely, 2^{66999974631552} 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 66999974631552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96571575488700).

66999974631552 is an abundant number, since it is smaller than the sum of its proper divisors (126143176345848).

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

66999974631552 is a wasteful number, since it uses less digits than its factorization.

66999974631552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45695 (or 45680 counting only the distinct ones).

The product of its digits is 5952139200, while the sum is 81.

The spelling of 66999974631552 in words is "sixty-six trillion, nine hundred ninety-nine billion, nine hundred seventy-four million, six hundred thirty-one thousand, five hundred fifty-two".