646601 has 4 divisors (see below), whose sum is σ = 652752. Its totient is φ = 640452.

The previous prime is 646577. The next prime is 646609. The reversal of 646601 is 106646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 106646 = 2 ⋅53323.

It is a cyclic number.

It is not a de Polignac number, because 646601 - 2⁶ = 646537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (646609) 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, 2915 + ... + 3128.

It is an arithmetic number, because the mean of its divisors is an integer number (163188).

2⁶⁴⁶⁶⁰¹ is an apocalyptic number.

It is an amenable number.

646601 is a deficient number, since it is larger than the sum of its proper divisors (6151).

646601 is a wasteful number, since it uses less digits than its factorization.

646601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6150.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 646601 is about 804.1150415208. The cubic root of 646601 is about 86.4726544365.

The spelling of 646601 in words is "six hundred forty-six thousand, six hundred one".