8821640 has 32 divisors (see below), whose sum is σ = 21017880. Its totient is φ = 3320832.

The previous prime is 8821633. The next prime is 8821661. The reversal of 8821640 is 461288.

It can be written as a sum of positive squares in 4 ways, for example, as 5354596 + 3467044 = 2314^2 + 1862^2 .

It is a super-3 number, since 3×8821640³ (a number of 22 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5807 + ... + 7166.

Almost surely, 2^8821640 is an apocalyptic number.

It is an amenable number.

8821640 is an abundant number, since it is smaller than the sum of its proper divisors (12196240).

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

8821640 is a wasteful number, since it uses less digits than its factorization.

8821640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13001 (or 12997 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 8821640 is about 2970.1245765119. The cubic root of 8821640 is about 206.6251159385.

The spelling of 8821640 in words is "eight million, eight hundred twenty-one thousand, six hundred forty".