8690221 has 2 divisors, whose sum is σ = 8690222. Its totient is φ = 8690220.

The previous prime is 8690203. The next prime is 8690267. The reversal of 8690221 is 1220968.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7502121 + 1188100 = 2739^2 + 1090^2 .

It is a cyclic number.

It is not a de Polignac number, because 8690221 - 2⁷ = 8690093 is a prime.

It is a Chen prime.

8690221 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 8690221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8690291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4345110 + 4345111.

It is an arithmetic number, because the mean of its divisors is an integer number (4345111).

Almost surely, 2^8690221 is an apocalyptic number.

It is an amenable number.

8690221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8690221 is an equidigital number, since it uses as much as digits as its factorization.

8690221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 8690221 is about 2947.9180789160. The cubic root of 8690221 is about 205.5939230819.

It can be divided in two parts, 8690 and 221, that added together give a triangular number (8911 = T₁₃₃).

The spelling of 8690221 in words is "eight million, six hundred ninety thousand, two hundred twenty-one".