Search a number
-
+
221021197 is a prime number
BaseRepresentation
bin11010010110010…
…00010000001101
3120101220001002021
431023020100031
5423040134242
633533130141
75322435445
oct1513102015
9511801067
10221021197
11103840551
1262029951
1336a37497
14214d5125
151460cb67
hexd2c840d

221021197 has 2 divisors, whose sum is σ = 221021198. Its totient is φ = 221021196.

The previous prime is 221021179. The next prime is 221021221. The reversal of 221021197 is 791120122.

Together with previous prime (221021179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 216119401 + 4901796 = 14701^2 + 2214^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021197 - 27 = 221021069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221021137) 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, 110510598 + 110510599.

It is an arithmetic number, because the mean of its divisors is an integer number (110510599).

Almost surely, 2221021197 is an apocalyptic number.

It is an amenable number.

221021197 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021197 is an equidigital number, since it uses as much as digits as its factorization.

221021197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 221021197 is about 14866.7816624850. The cubic root of 221021197 is about 604.6136886766.

The spelling of 221021197 in words is "two hundred twenty-one million, twenty-one thousand, one hundred ninety-seven".