66200550173 has 4 divisors (see below), whose sum is σ = 66807894780. Its totient is φ = 65593205568.

The previous prime is 66200550167. The next prime is 66200550179. The reversal of 66200550173 is 37105500266.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37105500266 = 2 ⋅18552750133.

It is an interprime number because it is at equal distance from previous prime (66200550167) and next prime (66200550179).

It can be written as a sum of positive squares in 2 ways, for example, as 51983088004 + 14217462169 = 227998^2 + 119237^2 .

It is a cyclic number.

It is not a de Polignac number, because 66200550173 - 2¹² = 66200546077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66200550179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 303672140 + ... + 303672357.

It is an arithmetic number, because the mean of its divisors is an integer number (16701973695).

Almost surely, 2^66200550173 is an apocalyptic number.

It is an amenable number.

66200550173 is a deficient number, since it is larger than the sum of its proper divisors (607344607).

66200550173 is a wasteful number, since it uses less digits than its factorization.

66200550173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607344606.

The product of its (nonzero) digits is 37800, while the sum is 35.

The spelling of 66200550173 in words is "sixty-six billion, two hundred million, five hundred fifty thousand, one hundred seventy-three".