646565013 has 6 divisors (see below), whose sum is σ = 933927254. Its totient is φ = 431043336.

The previous prime is 646565009. The next prime is 646565021. The reversal of 646565013 is 310565646.

646565013 is a `hidden beast` number, since 646 + 5 + 6 + 5 + 0 + 1 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 580906404 + 65658609 = 24102^2 + 8103^2 .

It is not a de Polignac number, because 646565013 - 2² = 646565009 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646565053) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35920270 + ... + 35920287.

Almost surely, 2^646565013 is an apocalyptic number.

It is an amenable number.

646565013 is a deficient number, since it is larger than the sum of its proper divisors (287362241).

646565013 is a wasteful number, since it uses less digits than its factorization.

646565013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71840563 (or 71840560 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 646565013 is about 25427.6426945165. The cubic root of 646565013 is about 864.7105017605.

The spelling of 646565013 in words is "six hundred forty-six million, five hundred sixty-five thousand, thirteen".