63856640 has 56 divisors (see below), whose sum is σ = 153344880. Its totient is φ = 25526272.

The previous prime is 63856627. The next prime is 63856649. The reversal of 63856640 is 4665836.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 63856594 and 63856603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63856649) 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, 40181 + ... + 41739.

Almost surely, 2^63856640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 63856640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76672440).

63856640 is an abundant number, since it is smaller than the sum of its proper divisors (89488240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

63856640 is an equidigital number, since it uses as much as digits as its factorization.

63856640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1590 (or 1566 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 63856640 is about 7991.0349767724. The cubic root of 63856640 is about 399.7011100510.

The spelling of 63856640 in words is "sixty-three million, eight hundred fifty-six thousand, six hundred forty".