6820400 has 90 divisors (see below), whose sum is σ = 17701620. Its totient is φ = 2524160.

The previous prime is 6820393. The next prime is 6820421. The reversal of 6820400 is 40286.

It is a Harshad number since it is a multiple of its sum of digits (20).

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 in 17 ways as a sum of consecutive naturals, for example, 115571 + ... + 115629.

Almost surely, 2^6820400 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 6820400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8850810).

6820400 is an abundant number, since it is smaller than the sum of its proper divisors (10881220).

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

6820400 is a wasteful number, since it uses less digits than its factorization.

6820400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 6820400 is about 2611.5895542753. The cubic root of 6820400 is about 189.6429119461.

Adding to 6820400 its reverse (40286), we get a palindrome (6860686).

The spelling of 6820400 in words is "six million, eight hundred twenty thousand, four hundred".