8621821920 has 48 divisors (see below), whose sum is σ = 27158740560. Its totient is φ = 2299152384.

The previous prime is 8621821909. The next prime is 8621821921. The reversal of 8621821920 is 291281268.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8621821921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8980585 + ... + 8981544.

It is an arithmetic number, because the mean of its divisors is an integer number (565807095).

Almost surely, 2^8621821920 is an apocalyptic number.

8621821920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8621821920 is an abundant number, since it is smaller than the sum of its proper divisors (18536918640).

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

8621821920 is a wasteful number, since it uses less digits than its factorization.

8621821920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17962147 (or 17962139 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 8621821920 is about 92853.7663210276. The cubic root of 8621821920 is about 2050.5310478269.

The spelling of 8621821920 in words is "eight billion, six hundred twenty-one million, eight hundred twenty-one thousand, nine hundred twenty".