646565647 has 8 divisors (see below), whose sum is σ = 795773216. Its totient is φ = 511568352.

The previous prime is 646565597. The next prime is 646565651. The reversal of 646565647 is 746565646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646565647 - 2¹⁵ = 646532879 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646565647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646565347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3552468 + ... + 3552649.

It is an arithmetic number, because the mean of its divisors is an integer number (99471652).

Almost surely, 2^646565647 is an apocalyptic number.

646565647 is a deficient number, since it is larger than the sum of its proper divisors (149207569).

646565647 is a wasteful number, since it uses less digits than its factorization.

646565647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7105137.

The product of its digits is 3628800, while the sum is 49.

The square root of 646565647 is about 25427.6551612609. The cubic root of 646565647 is about 864.7107843958.

Subtracting 646565647 from its reverse (746565646), we obtain a palindrome (99999999).

The spelling of 646565647 in words is "six hundred forty-six million, five hundred sixty-five thousand, six hundred forty-seven".