8221840 has 40 divisors (see below), whose sum is σ = 20855808. Its totient is φ = 2989440.

The previous prime is 8221831. The next prime is 8221841. The reversal of 8221840 is 481228.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (8221841) 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, 3792 + ... + 5551.

Almost surely, 2^8221840 is an apocalyptic number.

8221840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8221840 is an abundant number, since it is smaller than the sum of its proper divisors (12633968).

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

8221840 is a wasteful number, since it uses less digits than its factorization.

8221840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9367 (or 9361 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 8221840 is about 2867.3751062601. The cubic root of 8221840 is about 201.8318373025.

It can be divided in two parts, 822 and 1840, that added together give a palindrome (2662).

The spelling of 8221840 in words is "eight million, two hundred twenty-one thousand, eight hundred forty".