646841405 has 20 divisors (see below), whose sum is σ = 905540892. Its totient is φ = 443540160.

The previous prime is 646841369. The next prime is 646841417. The reversal of 646841405 is 504148646.

It can be written as a sum of positive squares in 2 ways, for example, as 289102009 + 357739396 = 17003^2 + 18914^2 .

It is not a de Polignac number, because 646841405 - 2¹² = 646837309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 14936 + ... + 38945.

Almost surely, 2^646841405 is an apocalyptic number.

It is an amenable number.

646841405 is a deficient number, since it is larger than the sum of its proper divisors (258699487).

646841405 is an frugal number, since it uses more digits than its factorization.

646841405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53914 (or 53893 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 38.

The square root of 646841405 is about 25433.0769864757. The cubic root of 646841405 is about 864.8336989708.

The spelling of 646841405 in words is "six hundred forty-six million, eight hundred forty-one thousand, four hundred five".