643686346 has 8 divisors (see below), whose sum is σ = 974903904. Its totient is φ = 318718380.

The previous prime is 643686301. The next prime is 643686361.

643686346 is nontrivially palindromic in base 10.

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

It is a super-2 number, since 2×643686346² = 828664224053663432, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643686296 and 643686305.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1562140 + ... + 1562551.

It is an arithmetic number, because the mean of its divisors is an integer number (121862988).

Almost surely, 2^643686346 is an apocalyptic number.

643686346 is a deficient number, since it is larger than the sum of its proper divisors (331217558).

643686346 is a wasteful number, since it uses less digits than its factorization.

643686346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124796.

The product of its digits is 1492992, while the sum is 46.

The square root of 643686346 is about 25370.9744787227. The cubic root of 643686346 is about 863.4252909937.

The spelling of 643686346 in words is "six hundred forty-three million, six hundred eighty-six thousand, three hundred forty-six".