8951221 has 2 divisors, whose sum is σ = 8951222. Its totient is φ = 8951220.

The previous prime is 8951213. The next prime is 8951249. The reversal of 8951221 is 1221598.

It is an a-pointer prime, because the next prime (8951249) can be obtained adding 8951221 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., 8820900 + 130321 = 2970^2 + 361^2 .

It is a cyclic number.

It is not a de Polignac number, because 8951221 - 2³ = 8951213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8951221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8951251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4475610 + 4475611.

It is an arithmetic number, because the mean of its divisors is an integer number (4475611).

Almost surely, 2^8951221 is an apocalyptic number.

It is an amenable number.

8951221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8951221 is an equidigital number, since it uses as much as digits as its factorization.

8951221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 28.

The square root of 8951221 is about 2991.8591210149. The cubic root of 8951221 is about 207.6319072261.

It can be divided in two parts, 895 and 1221, that added together give a square (2116 = 46²).

The spelling of 8951221 in words is "eight million, nine hundred fifty-one thousand, two hundred twenty-one".