646908841 has 4 divisors (see below), whose sum is σ = 652633812. Its totient is φ = 641183872.

The previous prime is 646908817. The next prime is 646908869. The reversal of 646908841 is 148809646.

646908841 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 302620816 + 344288025 = 17396^2 + 18555^2 .

It is a cyclic number.

It is not a de Polignac number, because 646908841 - 2⁵ = 646908809 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646908791 and 646908800.

It is not an unprimeable number, because it can be changed into a prime (646908881) 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, 2862316 + ... + 2862541.

It is an arithmetic number, because the mean of its divisors is an integer number (163158453).

Almost surely, 2^646908841 is an apocalyptic number.

It is an amenable number.

646908841 is a deficient number, since it is larger than the sum of its proper divisors (5724971).

646908841 is a wasteful number, since it uses less digits than its factorization.

646908841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5724970.

The product of its (nonzero) digits is 331776, while the sum is 46.

The square root of 646908841 is about 25434.4027057841. The cubic root of 646908841 is about 864.8637521380.

The spelling of 646908841 in words is "six hundred forty-six million, nine hundred eight thousand, eight hundred forty-one".