6440220828 has 72 divisors (see below), whose sum is σ = 16386305936. Its totient is φ = 2132697600.

The previous prime is 6440220817. The next prime is 6440220847. The reversal of 6440220828 is 8280220446.

It is a happy number.

6440220828 is a `hidden beast` number, since 6 + 440 + 2 + 208 + 2 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 6440220792 and 6440220801.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5734275 + ... + 5735397.

Almost surely, 2^6440220828 is an apocalyptic number.

It is an amenable number.

6440220828 is an abundant number, since it is smaller than the sum of its proper divisors (9946085108).

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

6440220828 is a wasteful number, since it uses less digits than its factorization.

6440220828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2035 (or 2030 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 36.

The square root of 6440220828 is about 80250.9864612268. The cubic root of 6440220828 is about 1860.5167589490.

The spelling of 6440220828 in words is "six billion, four hundred forty million, two hundred twenty thousand, eight hundred twenty-eight".