646907 has 4 divisors (see below), whose sum is σ = 648960. Its totient is φ = 644856.

The previous prime is 646897. The next prime is 646909. The reversal of 646907 is 709646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646907 - 2⁶ = 646843 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (646909) 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, 443 + ... + 1220.

It is an arithmetic number, because the mean of its divisors is an integer number (162240).

2⁶⁴⁶⁹⁰⁷ is an apocalyptic number.

646907 is a deficient number, since it is larger than the sum of its proper divisors (2053).

646907 is a wasteful number, since it uses less digits than its factorization.

646907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2052.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 646907 is about 804.3052902972. The cubic root of 646907 is about 86.4862931715.

The spelling of 646907 in words is "six hundred forty-six thousand, nine hundred seven".