Search a number
-
+
10001221 is a prime number
BaseRepresentation
bin100110001001…
…101101000101
3200211010002121
4212021231011
510030014341
6554205541
7151003036
oct46115505
920733077
1010001221
11571107a
1234238b1
1320c22a9
141484a8d
15d284d1
hex989b45

10001221 has 2 divisors, whose sum is σ = 10001222. Its totient is φ = 10001220.

The previous prime is 10001213. The next prime is 10001227. The reversal of 10001221 is 12210001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7784100 + 2217121 = 2790^2 + 1489^2 .

It is a cyclic number.

It is not a de Polignac number, because 10001221 - 23 = 10001213 is a prime.

10001221 is a modest number, since divided by 1221 gives 10 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10001227) 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, 5000610 + 5000611.

It is an arithmetic number, because the mean of its divisors is an integer number (5000611).

Almost surely, 210001221 is an apocalyptic number.

It is an amenable number.

10001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

10001221 is an equidigital number, since it uses as much as digits as its factorization.

10001221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 10001221 is about 3162.4707113268. The cubic root of 10001221 is about 215.4522371955.

Adding to 10001221 its reverse (12210001), we get a palindrome (22211222).

The spelling of 10001221 in words is "ten million, one thousand, two hundred twenty-one".