66155721670600 has 96 divisors (see below), whose sum is σ = 155549778942600. Its totient is φ = 26163361382400.

The previous prime is 66155721670589. The next prime is 66155721670631. The reversal of 66155721670600 is 607612755166.

It can be written as a sum of positive squares in 12 ways, for example, as 963888041284 + 65191833629316 = 981778^2 + 8074146^2 .

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, 316041172 + ... + 316250428.

Almost surely, 2^{66155721670600} 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 66155721670600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77774889471300).

66155721670600 is an abundant number, since it is smaller than the sum of its proper divisors (89394057272000).

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

66155721670600 is a wasteful number, since it uses less digits than its factorization.

66155721670600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227123 (or 227114 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 52.

The spelling of 66155721670600 in words is "sixty-six trillion, one hundred fifty-five billion, seven hundred twenty-one million, six hundred seventy thousand, six hundred".