66396161 has 8 divisors (see below), whose sum is σ = 71619240. Its totient is φ = 61189632.

The previous prime is 66396149. The next prime is 66396163. The reversal of 66396161 is 16169366.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3352561 + 63043600 = 1831^2 + 7940^2 .

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 66396161 - 2¹⁴ = 66379777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66396163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4955 + ... + 12543.

It is an arithmetic number, because the mean of its divisors is an integer number (8952405).

It is a Proth number, since it is equal to 8105 ⋅ 2¹³ + 1 and 8105 < 2¹³.

Almost surely, 2^66396161 is an apocalyptic number.

It is an amenable number.

66396161 is a deficient number, since it is larger than the sum of its proper divisors (5223079).

66396161 is a wasteful number, since it uses less digits than its factorization.

66396161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8275.

The product of its digits is 34992, while the sum is 38.

The square root of 66396161 is about 8148.3839502076. The cubic root of 66396161 is about 404.9309662349.

The spelling of 66396161 in words is "sixty-six million, three hundred ninety-six thousand, one hundred sixty-one".