648028821 has 32 divisors (see below), whose sum is σ = 969163776. Its totient is φ = 381744000.

The previous prime is 648028819. The next prime is 648028837. The reversal of 648028821 is 128820846.

It is not a de Polignac number, because 648028821 - 2¹ = 648028819 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 648028821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648028861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 447120 + ... + 448566.

It is an arithmetic number, because the mean of its divisors is an integer number (30286368).

Almost surely, 2^648028821 is an apocalyptic number.

It is an amenable number.

648028821 is a deficient number, since it is larger than the sum of its proper divisors (321134955).

648028821 is a wasteful number, since it uses less digits than its factorization.

648028821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1833.

The product of its (nonzero) digits is 49152, while the sum is 39.

The square root of 648028821 is about 25456.4102143252. The cubic root of 648028821 is about 865.3625713383.

The spelling of 648028821 in words is "six hundred forty-eight million, twenty-eight thousand, eight hundred twenty-one".