61666205 has 8 divisors (see below), whose sum is σ = 74679000. Its totient is φ = 48879936.

The previous prime is 61666201. The next prime is 61666211. The reversal of 61666205 is 50266616.

It can be written as a sum of positive squares in 4 ways, for example, as 12020089 + 49646116 = 3467^2 + 7046^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61666205 - 2² = 61666201 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61666201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56030 + ... + 57119.

It is an arithmetic number, because the mean of its divisors is an integer number (9334875).

Almost surely, 2^61666205 is an apocalyptic number.

It is an amenable number.

61666205 is a deficient number, since it is larger than the sum of its proper divisors (13012795).

61666205 is a wasteful number, since it uses less digits than its factorization.

61666205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113263.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 61666205 is about 7852.7832645502. The cubic root of 61666205 is about 395.0776005205.

The spelling of 61666205 in words is "sixty-one million, six hundred sixty-six thousand, two hundred five".