646644351 has 16 divisors (see below), whose sum is σ = 914354784. Its totient is φ = 405095424.

The previous prime is 646644337. The next prime is 646644359. The reversal of 646644351 is 153446646.

646644351 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 646644351 - 2⁷ = 646644223 is a prime.

It is a super-2 number, since 2×646644351² = 836297833360422402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646644359) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23595 + ... + 43011.

It is an arithmetic number, because the mean of its divisors is an integer number (57147174).

Almost surely, 2^646644351 is an apocalyptic number.

646644351 is a deficient number, since it is larger than the sum of its proper divisors (267710433).

646644351 is a wasteful number, since it uses less digits than its factorization.

646644351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20090.

The product of its digits is 207360, while the sum is 39.

The square root of 646644351 is about 25429.2027204944. The cubic root of 646644351 is about 864.7458689675.

The spelling of 646644351 in words is "six hundred forty-six million, six hundred forty-four thousand, three hundred fifty-one".