648691 has 4 divisors (see below), whose sum is σ = 651112. Its totient is φ = 646272.

The previous prime is 648689. The next prime is 648709. The reversal of 648691 is 196846.

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 648691 - 2¹ = 648689 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 (648631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 750 + ... + 1363.

It is an arithmetic number, because the mean of its divisors is an integer number (162778).

2⁶⁴⁸⁶⁹¹ is an apocalyptic number.

648691 is a deficient number, since it is larger than the sum of its proper divisors (2421).

648691 is a wasteful number, since it uses less digits than its factorization.

648691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2420.

The product of its digits is 10368, while the sum is 34.

The square root of 648691 is about 805.4135583661. The cubic root of 648691 is about 86.5657223796.

The spelling of 648691 in words is "six hundred forty-eight thousand, six hundred ninety-one".