6821617920 has 144 divisors (see below), whose sum is σ = 23462601792. Its totient is φ = 1679155200.

The previous prime is 6821617919. The next prime is 6821617949. The reversal of 6821617920 is 297161286.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18406 + ... + 118245.

Almost surely, 2^6821617920 is an apocalyptic number.

6821617920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6821617920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11731300896).

6821617920 is an abundant number, since it is smaller than the sum of its proper divisors (16640983872).

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

6821617920 is a wasteful number, since it uses less digits than its factorization.

6821617920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136688 (or 136674 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 6821617920 is about 82593.0863934748. The cubic root of 6821617920 is about 1896.5419946338.

The spelling of 6821617920 in words is "six billion, eight hundred twenty-one million, six hundred seventeen thousand, nine hundred twenty".