8081221 has 2 divisors, whose sum is σ = 8081222. Its totient is φ = 8081220.

The previous prime is 8081197. The next prime is 8081237. The reversal of 8081221 is 1221808.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7672900 + 408321 = 2770^2 + 639^2 .

It is a cyclic number.

It is not a de Polignac number, because 8081221 - 2⁷ = 8081093 is a prime.

It is a super-2 number, since 2×8081221² = 130612265701682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 8081192 and 8081201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8084221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4040610 + 4040611.

It is an arithmetic number, because the mean of its divisors is an integer number (4040611).

Almost surely, 2^8081221 is an apocalyptic number.

It is an amenable number.

8081221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8081221 is an equidigital number, since it uses as much as digits as its factorization.

8081221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 8081221 is about 2842.7488457477. The cubic root of 8081221 is about 200.6745639263.

The spelling of 8081221 in words is "eight million, eighty-one thousand, two hundred twenty-one".