646551647 has 4 divisors (see below), whose sum is σ = 738916176. Its totient is φ = 554187120.

The previous prime is 646551637. The next prime is 646551683. The reversal of 646551647 is 746155646.

646551647 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 is a cyclic number.

It is not a de Polignac number, because 646551647 - 2⁸ = 646551391 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646551598 and 646551607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646551637) 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, 46182254 + ... + 46182267.

It is an arithmetic number, because the mean of its divisors is an integer number (184729044).

Almost surely, 2^646551647 is an apocalyptic number.

646551647 is a deficient number, since it is larger than the sum of its proper divisors (92364529).

646551647 is an equidigital number, since it uses as much as digits as its factorization.

646551647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92364528.

The product of its digits is 604800, while the sum is 44.

The square root of 646551647 is about 25427.3798689523. The cubic root of 646551647 is about 864.7045431949.

The spelling of 646551647 in words is "six hundred forty-six million, five hundred fifty-one thousand, six hundred forty-seven".