646421071256 has 32 divisors (see below), whose sum is σ = 1234475802000. Its totient is φ = 317279778816.

The previous prime is 646421071253. The next prime is 646421071273. The reversal of 646421071256 is 652170124646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646421071253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3166841 + ... + 3364776.

Almost surely, 2^646421071256 is an apocalyptic number.

It is an amenable number.

646421071256 is a deficient number, since it is larger than the sum of its proper divisors (588054730744).

646421071256 is a wasteful number, since it uses less digits than its factorization.

646421071256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6531851 (or 6531847 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 646421071256 in words is "six hundred forty-six billion, four hundred twenty-one million, seventy-one thousand, two hundred fifty-six".