66404161 has 8 divisors (see below), whose sum is σ = 67409280. Its totient is φ = 65403312.

The previous prime is 66404141. The next prime is 66404189. The reversal of 66404161 is 16140466.

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 66404161 - 2⁷ = 66404033 is a prime.

It is a super-2 number, since 2×66404161² = 8819025196227842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66404101) 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, 43731 + ... + 45223.

It is an arithmetic number, because the mean of its divisors is an integer number (8426160).

Almost surely, 2^66404161 is an apocalyptic number.

It is an amenable number.

66404161 is a deficient number, since it is larger than the sum of its proper divisors (1005119).

66404161 is a wasteful number, since it uses less digits than its factorization.

66404161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 66404161 is about 8148.8748303063. The cubic root of 66404161 is about 404.9472288099.

It can be divided in two parts, 6640 and 4161, that added together give a palindrome (10801).

The spelling of 66404161 in words is "sixty-six million, four hundred four thousand, one hundred sixty-one".