648139856 has 120 divisors (see below), whose sum is σ = 1656456480. Its totient is φ = 242839296.

The previous prime is 648139781. The next prime is 648139873. The reversal of 648139856 is 658931846.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 191975 + ... + 195321.

It is an arithmetic number, because the mean of its divisors is an integer number (13803804).

Almost surely, 2^648139856 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 648139856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (828228240).

648139856 is an abundant number, since it is smaller than the sum of its proper divisors (1008316624).

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

648139856 is a wasteful number, since it uses less digits than its factorization.

648139856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3401 (or 3388 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 50.

The square root of 648139856 is about 25458.5910057882. The cubic root of 648139856 is about 865.4119930321.

The spelling of 648139856 in words is "six hundred forty-eight million, one hundred thirty-nine thousand, eight hundred fifty-six".