646056805 has 4 divisors (see below), whose sum is σ = 775268172. Its totient is φ = 516845440.

The previous prime is 646056793. The next prime is 646056847. The reversal of 646056805 is 508650646.

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 274299844 + 371756961 = 16562^2 + 19281^2 .

It is not a de Polignac number, because 646056805 - 2¹⁵ = 646024037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64605676 + ... + 64605685.

It is an arithmetic number, because the mean of its divisors is an integer number (193817043).

Almost surely, 2^646056805 is an apocalyptic number.

It is an amenable number.

646056805 is a deficient number, since it is larger than the sum of its proper divisors (129211367).

646056805 is a wasteful number, since it uses less digits than its factorization.

646056805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129211366.

The product of its (nonzero) digits is 172800, while the sum is 40.

The square root of 646056805 is about 25417.6475111290. The cubic root of 646056805 is about 864.4838847024.

The spelling of 646056805 in words is "six hundred forty-six million, fifty-six thousand, eight hundred five".