646171256 has 32 divisors (see below), whose sum is σ = 1246476000. Its totient is φ = 313808256.

The previous prime is 646171217. The next prime is 646171259. The reversal of 646171256 is 652171646.

It is a super-4 number, since 4×646171256⁴ (a number of 36 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646171259) 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, 208325 + ... + 211403.

It is an arithmetic number, because the mean of its divisors is an integer number (38952375).

Almost surely, 2^646171256 is an apocalyptic number.

It is an amenable number.

646171256 is a deficient number, since it is larger than the sum of its proper divisors (600304744).

646171256 is a wasteful number, since it uses less digits than its factorization.

646171256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3831 (or 3827 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 646171256 is about 25419.8988196255. The cubic root of 646171256 is about 864.5349303702.

The spelling of 646171256 in words is "six hundred forty-six million, one hundred seventy-one thousand, two hundred fifty-six".