6821128 has 8 divisors (see below), whose sum is σ = 12789630. Its totient is φ = 3410560.

The previous prime is 6821117. The next prime is 6821141. The reversal of 6821128 is 8211286.

It can be written as a sum of positive squares in only one way, i.e., 3992004 + 2829124 = 1998^2 + 1682^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 6821096 and 6821105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 426313 + ... + 426328.

Almost surely, 2^6821128 is an apocalyptic number.

It is an amenable number.

6821128 is a deficient number, since it is larger than the sum of its proper divisors (5968502).

6821128 is a wasteful number, since it uses less digits than its factorization.

6821128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852647 (or 852643 counting only the distinct ones).

The product of its digits is 1536, while the sum is 28.

The square root of 6821128 is about 2611.7289292727. The cubic root of 6821128 is about 189.6496591128.

It can be divided in two parts, 682112 and 8, that multiplied together give a square (5456896 = 2336²).

The spelling of 6821128 in words is "six million, eight hundred twenty-one thousand, one hundred twenty-eight".