66409001 has 4 divisors (see below), whose sum is σ = 66469572. Its totient is φ = 66348432.

The previous prime is 66408989. The next prime is 66409003. The reversal of 66409001 is 10090466.

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 25755625 + 40653376 = 5075^2 + 6376^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66409001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66409003) 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, 28610 + ... + 30843.

It is an arithmetic number, because the mean of its divisors is an integer number (16617393).

Almost surely, 2^66409001 is an apocalyptic number.

It is an amenable number.

66409001 is a deficient number, since it is larger than the sum of its proper divisors (60571).

66409001 is a wasteful number, since it uses less digits than its factorization.

66409001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60570.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 66409001 is about 8149.1717984099. The cubic root of 66409001 is about 404.9570670336.

Adding to 66409001 its reverse (10090466), we get a palindrome (76499467).

The spelling of 66409001 in words is "sixty-six million, four hundred nine thousand, one".