66610205 has 4 divisors (see below), whose sum is σ = 79932252. Its totient is φ = 53288160.

The previous prime is 66610189. The next prime is 66610213. The reversal of 66610205 is 50201666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28922884 + 37687321 = 5378^2 + 6139^2 .

It is not a de Polignac number, because 66610205 - 2⁴ = 66610189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6661016 + ... + 6661025.

It is an arithmetic number, because the mean of its divisors is an integer number (19983063).

Almost surely, 2^66610205 is an apocalyptic number.

It is an amenable number.

66610205 is a deficient number, since it is larger than the sum of its proper divisors (13322047).

66610205 is a wasteful number, since it uses less digits than its factorization.

66610205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13322046.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 66610205 is about 8161.5075200602. The cubic root of 66610205 is about 405.3656302865.

The spelling of 66610205 in words is "sixty-six million, six hundred ten thousand, two hundred five".