8900821 has 2 divisors, whose sum is σ = 8900822. Its totient is φ = 8900820.

The previous prime is 8900807. The next prime is 8900849. The reversal of 8900821 is 1280098.

8900821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (8900849) can be obtained adding 8900821 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4536900 + 4363921 = 2130^2 + 2089^2 .

It is a cyclic number.

It is not a de Polignac number, because 8900821 - 2⁵ = 8900789 is a prime.

It is a super-2 number, since 2×8900821² = 158449228948082, which contains 22 as substring.

It is an Ulam number.

8900821 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 8900821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8900861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4450410 + 4450411.

It is an arithmetic number, because the mean of its divisors is an integer number (4450411).

Almost surely, 2^8900821 is an apocalyptic number.

It is an amenable number.

8900821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8900821 is an equidigital number, since it uses as much as digits as its factorization.

8900821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 8900821 is about 2983.4243747747. The cubic root of 8900821 is about 207.2414818956.

The spelling of 8900821 in words is "eight million, nine hundred thousand, eight hundred twenty-one".